Dielectric Material, Method for Preparing the Same, Device Comprising the Same, and Memory Cell

Abstract

Provided are a dielectric material, a method for preparing the same, a device including the same, and a memory cell. The dielectric material includes a compound represented by Formula 1, where, in Formula 1, M is a Group 2 element, A is a trivalent element, and 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1, and c + d = 1. [Formula 1] (1 - x)K a Na b NbO3·xM(A c Sb d )O3.

Description

[0001] Cross-reference to related applications

[0002] This application is based on and claims the benefit of priority from Korean Patent Application No. 10-2020-0090571 filed on July 21, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. Technical Field

[0003] The present disclosure relates to dielectric materials, methods of making the same, and devices including the same. Background Art

[0004] In response to the continued demand for miniaturization and higher capacity of electronic products, capacitors with smaller size and higher capacity than related art capacitors are needed. In order to achieve capacitors with smaller size and higher capacity, dielectric materials that can provide further improved dielectric properties are needed.

[0005] To manufacture multilayer ceramic capacitors (MLCCs), which are small-sized, high-capacity capacitors, the dielectric material layers need to be thin. This inevitably causes a rapid increase in the magnitude of the device's electric field, which can lead to a decrease in the dielectric's spontaneous polarization and, consequently, a significant drop in the dielectric constant. Consequently, there is a growing demand to replace existing dielectrics with dielectric materials that operate effectively in high electric field ranges. Summary of the Invention

[0006] Provided are dielectric materials that have improved structural stability and physical properties and operate efficiently in high electric field ranges.

[0007] A device including the dielectric material is provided.

[0008] A method for preparing the dielectric material is provided.

[0009] Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0010] According to one aspect, a dielectric material is provided, which includes a compound represented by Formula 1:

[0011] [Formula 1]

[0012] (1-x)K a Na b NbO3·xM(A c Sb d )O3

[0013] Among them, in Formula 1, K is potassium, Na is sodium, Nb is niobium, Sb is antimony, O is oxygen, M is a Group 2 element, A is a trivalent element, and 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1, and c + d = 1.

[0014] According to another aspect, there is provided a device including: a plurality of electrodes; and a dielectric material layer between the plurality of electrodes, wherein the dielectric material layer includes the above dielectric material.

[0015] The device may be a capacitor.

[0016] The device may be a multilayer capacitor including: a plurality of internal electrodes (inner electrodes); and a plurality of dielectric material layers alternately disposed between the plurality of internal electrodes.

[0017] According to another aspect, there is provided a method for preparing a dielectric material including a compound represented by Formula 1, the method including: mechanically grinding a mixture of a potassium salt, a sodium salt, a Nb compound, a compound containing M, a compound of A, and a Sb compound; and performing a first heat treatment in an oxidizing atmosphere, wherein the dielectric material includes a compound represented by Formula 1:

[0018] [Formula 1]

[0019] (1 - x)K a Na b NbO3·xM(A c Sb d )O3

[0020] Among them, in Formula 1, M is a Group 2 element, A is a trivalent element, and 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1, and c + d = 1. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other aspects, features, and advantages of some embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0022] Figures 1A to 1C is a conceptual diagram illustrating how the dielectric constant decreases due to the fixed spontaneous polarization in an existing thin - film ferroelectric material under a high electric field;

[0023] Figures 2A to 2C is a conceptual diagram illustrating that a relaxor ferroelectric material as a dielectric material according to an exemplary embodiment exhibits a high dielectric constant (permittivity) even under a high electric field due to polar nano - regions (PNRs) in the relaxor ferroelectric material;

[0024] Figure 3A and 3BDescribe the X-ray diffraction analysis results of the dielectric materials of Example 1, Example 4, and Comparative Example 1;

[0025] Figure 4 Describe the change in the dielectric constant according to temperature of the dielectric materials of Example 1, Example 4, and Comparative Example 1;

[0026] Figure 5 Describe the change in polarization according to the electric field in the dielectric materials of Example 1, Example 4, and Comparative Example 1;

[0027] Figure 6 is a schematic diagram of a multilayer ceramic capacitor (MLCC) according to an exemplary embodiment; and

[0028] Figure 7A Describe the circuit configuration of a memory cell of a memory device including a semiconductor device and a capacitor, Figure 7B is a schematic diagram showing a semiconductor device according to an exemplary embodiment. Detailed Description

[0029] Some exemplary embodiments will now be described in detail, the examples of which are shown in the accompanying drawings, where the same reference numerals always denote the same elements. In this regard, the present embodiments may have different forms and should not be construed as limited to the descriptions set forth herein. Therefore, the embodiments are described below only by referring to the accompanying drawings to explain aspects. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. The expression "at least one (kind) of" when before or after a list of elements modifies the entire list of elements and not individual elements of the list.

[0030] Hereinafter, embodiments of a dielectric material, a device including the same, and a method for preparing the dielectric material will be described in more detail.

[0031] The dielectric material according to an embodiment may include a compound represented by Formula 1:

[0032] [Formula 1]

[0033] (1-x)K a Na b NbO3·xM(A c Sb d )O3

[0034] Wherein, in Formula 1, M is a Group 2 element, A is a trivalent element, and 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1, and c + d = 1.

[0035] For example, in Formula 1, M may be at least one of Sr, Ca, Ba, and Mg, and A may be at least one of B, Al, Ga, In, Tl, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, and Dy.

[0036] In Formula 1, A may represent one or more elements selected from Group 13 elements and / or lanthanide elements, and may be, for example, at least one of B, Al, Ga, In, Tl, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

[0037] In Formula 1, x may be 0.01 to 0.3, for example, 0.05 to 0.2. When x is 0.01 to 0.3, this means that M (A c Sb d )The amount of O3 is 1 mol% to 30 mol%.

[0038] In order to manufacture a multilayer ceramic capacitor (MLCC), which is a small-sized, high-capacity capacitor, it is necessary to form a dielectric material layer with a small thickness. When the dielectric material layer is formed with a small thickness, it is inevitable that the magnitude of the electric field of the MLCC can increase rapidly. As a result, the spontaneous polarization of the dielectric material can be reduced, resulting in a significant decrease in the dielectric constant of the dielectric material layer. Therefore, there is a need to replace existing ferroelectric materials with ferroelectric materials that solve the above-mentioned problems and can operate effectively in the high electric field range.

[0039] In one or more example embodiments, the dielectric material as the ferroelectric material satisfying the above-mentioned characteristics may include a compound of Formula 1. The compound of Formula 1 may be K a Na b NbO3(KNN) dielectric material (one of the perovskite compounds with high dielectric properties) was M(A c Sb d )O3 substituted product. K a Na b NbO3(KNN) dielectric material can be, for example, (K 0.5 Na 0.5 )NbO3. Here, M(A c Sb d )O3 and the compound of Formula 1 including the same may each be in the form of a solid solution.

[0040] When in the form of a solid solution, the compound of Formula 1 may be c Sb d)O3 elements form a pseudo-cubic structure by modifying the lattice structure of the solid solution. As a result, the phase transition temperature of the matrix KNN can be lowered to near room temperature (25°C), resulting in an increase in the dielectric constant at room temperature. c Sb d For example, BSb is introduced into the sites of the elements constituting KNN to form defect clusters, M can act as a donor, and A c Sb d In the defect clusters described above, due to the polar nanoregions (PNRs), the dielectric material according to one or more embodiments can have a reduced AC sweep (frequency sweep) reaction energy barrier even under high electric fields. Thus, when the AC sweep reaction energy barrier is reduced, the polarization fixation phenomenon can be alleviated, thereby improving the dielectric constant reduction rate.

[0041] Hereinafter, an operating principle of a dielectric material according to one or more example embodiments will be described.

[0042] Figures 1A to 1C is a conceptual diagram illustrating how the dielectric constant decreases under high electric fields due to fixed spontaneous polarization in existing thin-film ferroelectric materials (eg, because the spontaneous polarization is fixed under high direct current (DC) voltage under high electric fields).

[0043] exist Figure 1A In the embodiment, the ferroelectric material 100 (whose thickness is reduced to a few nanometers according to high integration and miniaturization) may include KNN, for example (K 0.5 Na 0.5 )NbO3. The ferroelectric material 100 may include KNN domains 120 separated by boundaries 110. Each domain 120 of the ferroelectric material 100 may have a polarization 130. The polarization 130 may initially be randomly oriented in each domain 120. For example, when no electric field is applied to the ferroelectric material 100, the polarization 130 of each domain 120 may be as follows: Figure 1A When a high direct current (DC) voltage (e.g., DC bias 140) is applied to the ferroelectric material 100, the ferroelectric material 100 is placed under a high electric field. As a result, the polarizations 130 of the domains 120 of the ferroelectric material 100 can be mostly aligned in the same direction as the DC bias 140, so that the ferroelectric material 100 as a whole exhibits a polarization in the same direction as the DC bias 140. Thereafter, as Figure 1C, even when the direction of the AC bias 150 is changed to a direction opposite to the DC bias 140 while the DC bias 140 is present in the ferroelectric material 100, the direction of the polarization 130 of each domain 120 does not change and thus remains in the same direction as the DC bias 140. Thus, after the polarization 130 of the ferroelectric material 100 is fixed in the direction of the DC bias 140, the polarization 130 may not respond to changes in the AC bias 150, which rapidly reduces the dielectric constant of the ferroelectric material 100. As a result, the ferroelectric material 100 may not function as a dielectric material.

[0044] Hereinafter, as a method for improving the degradation of ferroelectric properties (e.g., reduction in dielectric constant) occurring in ferroelectric materials due to high integration and miniaturization, a dielectric material including a compound represented by the above formula is provided as a novel dielectric material to which a mechanism for operating effectively even under high electric fields is applied.

[0045] The dielectric material according to one or more embodiments may be a ceramic ferroelectric that exhibits a higher dielectric constant than a conventional KNN even in a high electric field, even when a high DC voltage is applied. Such a ferroelectric material may include a portion with a low AC sweep energy barrier. Due to this portion having a low AC sweep energy barrier, the ferroelectric material may respond to AC sweeping even under high electric fields and exhibit a higher dielectric constant than a conventional KNN. For example, dielectric properties may be maintained even under high electric fields.

[0046] In one or more example embodiments, the compound of Formula 1 may be a relaxor ferroelectric material.

[0047] Figures 2A to 2C is a conceptual diagram illustrating that a relaxor ferroelectric material as a dielectric material according to example embodiments responds well to an AC bias under a high electric field, such as a high DC bias, due to polar nanoregions (PNRs) in the dielectric material and thus exhibits a high dielectric constant.

[0048] Reference Figures 2A to 2C , a relaxor ferroelectric material 200 as a dielectric material according to an example embodiment includes a ferroelectric material 205 exhibiting a first polarization characteristic and a polar region 210 included in the ferroelectric material 205 and exhibiting a second polarization characteristic. The first polarization characteristic and the second polarization characteristic may be different from each other. The first polarization characteristic and the second polarization characteristic may include spontaneous polarization characteristics. The relaxor ferroelectric material 200 may be represented as a relaxor ferroelectric material layer. The polar region 210 may be represented as a polar layer and / or a polar portion. The ferroelectric material 205 may be represented as a ferroelectric material layer. When applied to an electronic device (e.g., a capacitor), the ferroelectric material 205 may have a thickness of 1000 nm or less.

[0049] In one or more embodiments, according to example embodiments, the ferroelectric material 205 may be a dielectric material and / or a dielectric material layer. The polar region 210 may include a solid solution including a material different from the ferroelectric material 205. When the ferroelectric material 205 includes the compound of Formula 1, the relaxor ferroelectric material 200 including the polar region 210 may have a quasi-cubic crystal structure as a whole, and may not exhibit peaks corresponding to (002) and (004) in an X-ray diffraction spectrum.

[0050] For example, the polar region 210 may be a portion of the ferroelectric material 205 in which a primary element is replaced by a different element. When the ferroelectric material 205 is a KNN, the polar region 210 may be a region formed by a defect cluster in which K in the A site of the KNN is replaced by a first element different from K, and Nb in the B site of the KNN is replaced by a second element different from Nb. The defect cluster may be a polar nanoregion (PNR).

[0051] The first element may be an element that acts as a donor, and the second element may be an element that acts as an acceptor. The first element and the second element may have different ionic radii. In example embodiments, the ionic radius of the first element may be greater than the ionic radius of the second element. The amounts of the first element and the second element included in the relaxor ferroelectric material 200 may be the same.

[0052] The first element may be, for example, a Group 2 element (eg, at least one of Sr, Ca, Ba, and Mg). The second element may include, for example, A c Sb d (where A is a trivalent element).

[0053] Therefore, since the material of polar region 210 is different from that of ferroelectric material 205, the first polarization characteristic of ferroelectric material 205 may be different from the second polarization characteristic of polar region 210. Therefore, the energy barrier of ferroelectric material 205 and the energy barrier of polar region 210 in response to AC sweep 150 may be different from each other. In example embodiments, the energy barrier of polar region 210 in response to AC sweep 150 may be lower than the energy barrier of ferroelectric material 205. For this reason, as Figure 2B and Figure 2C As shown in FIG, when the relaxor ferroelectric material 200 is under a high DC bias 140, the total polarization of the ferroelectric material 205 is fixed in the direction of the DC bias 140 due to the high electric field caused by the DC bias 140, like the ferroelectric material 100 of FIG. 1 , and does not respond to the AC bias 150 applied to the relaxor ferroelectric material 200, but the polar region 210 can directly respond to the AC bias 150, and thus the polarization direction of the polar region 210 can change in response to the AC bias 150. In this way, the relaxor ferroelectric material 200 can exhibit a high dielectric constant even under a high electric field caused by a high DC voltage.

[0054] In Figures 2A to 2C the relaxor ferroelectric material 200, like the ferroelectric material 100 such as Figure 1A , the ferroelectric material 205 also includes a plurality of domains, although not shown for convenience. Each domain included in the ferroelectric material 205 may include a plurality of polar regions 210. The polarization characteristics of the regions other than the polar regions 210 in each domain may be different from those of the polar regions 210.

[0055] In one or more embodiments, the dielectric material may include, for example, a compound represented by Formula 2:

[0056] [Formula 2]

[0057] (1 - x)K a Na b NbO3·xSr(A c Sb d )O3

[0058] wherein, in Formula 2, A may be at least one of the following: B, Al, Ga, In, Tl, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1, and c + d = 1.

[0059] In Formula 2, for example, x may be 0.01 to 0.3 and / or 0.05 to 0.2.

[0060] The compound represented by Formula 1 may be a compound represented by at least one of Formula 3, Formula 4, Formula 5, and / or Formula 6:

[0061] [Formula 3]

[0062] (1 - x)K a Na b NbO3·xSr(B c Sb d )O3

[0063] wherein, in Formula 3, 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1, and c + d = 1;

[0064] [Formula 4]

[0065] (1 - x)K a Na b NbO3·xSr(Ga c Sb d )O3

[0066] Among them, in Formula 4, 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1, and c + d = 1;

[0067] [Formula 5]

[0068] (1 - x)K a Na b NbO3·xSr(Sc c Sb d )O3

[0069] Among them, in Formula 5, 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1, and c + d = 1; and

[0070] [Formula 6]

[0071] (1 - x)K a Na b NbO3·xSr(La c Sb d )O3

[0072] Among them, in Formula 6, 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1, and c + d = 1.

[0073] For example, in Formulas 3 to 6, x can be from 0.01 to 0.3, for example from 0.05 to 0.2.

[0074] As measured by X-ray diffraction analysis, the compound of Formula 1 can exhibit a main peak in the form of a broad single peak in the diffraction angle (2θ) region of 45° to 47°. The single peak can have a full width at half maximum (HWHM) of 0.475 to 0.507, for example 0.5.

[0075] The compound of Formula 1 can include, for example, at least one of the following: (1 - x)(K a Na b )NbO3·xSr(Ga c Sb d )O3, (1 - x)(K a Na b )NbO3·xSr(Sc c Sb d )O3, (1 - x)(K a Na b )NbO3·xSr(La c Sb d )O3, (1 - x)(K a Na b )NbO3·xSr(B c Sb d)O3、(1-x)(K a And b )NbO3·xSr(Al c Sb d )O3、(1-x)(K a And b )NbO3·xSr(In c Sb d )O3、(1-x)(K a And b )NbO3·xSr(Y c Sb d )O3、(1-x)(K a And b )NbO3·xSr(Ce c Sb d )O3、(1-x)(K a And b )NbO3·xSr(Nd c Sb d )O3、(1-x)(K a And b )NbO3·xSr(Gd c Sb d )O3、(1-x)(K a And b )NbO3·xSr(Sm c Sb d )O3、(1-x)(K a And b )NbO3·xSr(Eu c Sb d )O3、(1-x)(K a And b )NbO3·xSr(Tb c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Ga c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Sc c Sb d )O3、(1-x)(K a And b )NbO3·xCa(La c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Bc Sb d )O3、(1-x)(K a And b )NbO3·xCa(Al c Sb d )O3、(1-x)(K a And b )NbO3·xCa(In c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Y c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Ce c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Nd c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Gd c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Sm c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Eu c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Tb c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Ga c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Sc c Sb d )O3、(1-x)(K a And b )NbO3·xBa(La c Sb d )O3、(1-x)(K a Andb )NbO3·xBa(B c Sb d )O3、(1-x)(K a Na b )NbO3·xBa(Al c Sb d )O3、(1-x)(K a Na b )NbO3·xBa(In c Sb d )O3、(1-x)(K a Na b )NbO3·xBa(Y c Sb d )O3、(1-x)(K a Na b )NbO3·xBa(Ce c Sb d )O3、(1-x)(K a Na b )NbO3·xBa(Nd c Sb d )O3、(1-x)(K a Na b )NbO3·xBa(Gd c Sb d )O3、(1-x)(K a Na b )NbO3·xBa(Sm c Sb d )O3、(1-x)(K a Na b )NbO3·xBa(Eu c Sb d )O3, and / or (1-x)(K a Na b )NbO3·xBa(Tb c Sb d )O3.

[0076] In the formula, for example, x may be 0.01 to 0.3, a and b may each independently be 0.4 to 0.6, and c and d may each independently be 0.4 to 0.6. Here, the sum of a and b may be 1, and the sum of c and d may be 1.

[0077] In one or more embodiments, the compound of Formula 1 may be at least one of the following: (1-x)(K 0.5 Na 0.5 )NbO3·xSr(Ga 0.5 Sb 0.5)O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(Sc 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(La 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(B 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(Al 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(In 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(Y 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(Ce 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(Nd 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(Gd 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(Sm 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(Eu 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(Tb 0.5 Sb 0.5 )O3(1-x)(K 0.5 And 0.5 )NbO3·xCa(Ga0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Sc 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(La 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(B 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Al 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(In 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Y 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Ce 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Nd 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Gd 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Sm 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Eu 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Tb 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And0.5 ) NbO3·xBa(Ga 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(Sc 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(La 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(B 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(Al 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(In 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(Y 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(Ce 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(Nd 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(Gd 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(Sm 0.5 Sb 0.5 ) O3、(1 - x)(K 0.5 Na 0.5 ) NbO3·xBa(Eu 0.5 Sb 0.5 ) O3、and / or (1 - x)(K 0.5 Na 0.5 ) NbO3 - xBa(Tb 0.5 Sb 0.5)O3, wherein, in the above formula, x may be from 0.01 to 0.3.

[0078] The dielectric material including the compound represented by Formula 1 may have a composite phase crystal structure including at least one of an orthorhombic, cubic and / or tetragonal crystal structure. c Sb d )O3 content, the dielectric material may have a quasi-cubic phase. A quasi-cubic phase may refer to a cubic phase-like crystal structure. For example, a quasi-cubic phase may include a rhombic (hexagonal) crystal structure that mimics a cubic phase but has lower symmetry than the cubic phase. Therefore, the structural characteristics of the aggregate of the composite phases may exhibit a quasi-cubic phase.

[0079] The electric field-polarization plot for a dielectric material including the compound of Formula 1 can be represented as a linear curve proportional to the applied electric field, wherein the maximum polarization (Pmax) and polarization (Pr) of the dielectric material increase with M(A) c Sb d )The content of O3 increases and decreases.

[0080] In contrast, the conventional KNN may exhibit a typical ferroelectric hysteresis loop, while the electric field-polarization plot of the dielectric material as a solid solution according to one or more embodiments may be plotted as M(A) c Sb d )The increase of O3 content shows a linear curve.

[0081] The dielectric material according to one or more embodiments may have a dielectric constant of 610 or greater at room temperature (25° C.) and at 1 kHz to 1 MHz, thereby improving the dielectric properties of capacitors including the dielectric material and making it easier to manufacture smaller, thinner, and higher-capacity capacitors. The dielectric material according to one or more embodiments may have a dielectric constant of 800 or greater, 900 or greater, for example, 900 to 100,000, 1,000 to 30,000, 1,000 to 10,000, 1,050 to 5,000, and / or 1,100 to 1,900.

[0082] According to another aspect, a device may include: a plurality of electrodes; and a dielectric material layer between the plurality of electrodes, wherein the dielectric material layer includes the dielectric material according to one or more example embodiments.

[0083] The device may be, for example, a capacitor. The capacitor may include a plurality of internal electrodes and dielectric material layers alternately disposed between the plurality of internal electrodes.

[0084] The dielectric material layer may have a specific resistance of 1.0E+9Ωcm or greater, for example 1.0E+11Ωcm or greater and / or 1.2 to 4E+11Ωcm.As described above, the dielectric material layer may have good insulation properties.

[0085] By including the dielectric material according to the above-described embodiments, a device according to one or more embodiments may have improved dielectric characteristics, and thus, improved electrical characteristics.

[0086] The device can be used in electrical circuits, electronic circuits, electromagnetic circuits, and the like, and is not particularly limited, as long as the device provides an electrical output for an electrical input. The electrical input can be current and / or voltage, and the current can be direct current and / or alternating current. The electrical input can be intermittent input with a constant period and / or continuous input. For example, the device can store electrical energy, electrical signals, magnetic energy, and / or magnetic signals. The device can be a semiconductor device, a memory, a processor, and the like. The device can include, for example, a resistor, an inductor, a capacitor, and the like.

[0087] The device may be, for example, a capacitor. The capacitor may be, for example, a multilayer capacitor comprising: a plurality of internal electrodes; and the above-described dielectric material layers alternately disposed between the plurality of internal electrodes. The capacitor may have a standalone device form, such as a multilayer capacitor, but is not necessarily limited to such a form and may be included as part of a memory device. The capacitor may be, for example, a metal-insulator-metal (MIM) capacitor mounted in a memory device.

[0088] Reference Figure 6According to an embodiment, a multilayer capacitor 1 may include: a plurality of internal electrodes 12, and dielectric material layers 11 alternately arranged between the plurality of internal electrodes 12. The multilayer capacitor 1 may have a structure in which a plurality of internal electrodes 12 and dielectric material layers 11 are alternately stacked, and the dielectric material layers 11 may include a dielectric material according to one or more embodiments. Adjacent internal electrodes 12 may be electrically isolated from each other by the dielectric material layer 11 therebetween. In the multilayer capacitor 1, since the internal electrodes 12 and the dielectric material layers 11 are alternately stacked, the dielectric material layers 11 between the adjacent internal electrodes 12 may function as a single unit capacitor. In the multilayer capacitor 1, the number of alternately stacked internal electrodes 12 and the number of dielectric material layers 11 may each independently be, for example, 2 or more, 5 or more, 10 or more, 20 or more, 50 or more, 100 or more, 200 or more, 500 or more, 1,000 or more, 2,000 or more, 5,000 or more, and / or 10,000 or more. The multilayer capacitor 1 can provide capacitance by a stacked structure in which a plurality of unit capacitors are stacked. As the number of stacked internal electrodes 12 and dielectric material layers 11 increases, their contact area can increase, thereby improving capacitance. The internal electrodes 12 can be configured to have an area smaller than that of the dielectric material layer 11. The plurality of internal electrodes 12 can each have the same area, but adjacent internal electrodes 12 can be arranged so as not to be in the same position along the thickness direction of the multilayer capacitor 1 and to alternately partially protrude in the direction of the opposite side surfaces of the multilayer capacitor 1.

[0089] The internal electrode 12 can be formed, for example, by placing a conductive plate between dielectric material layers and / or using a conductive paste including a conductive material, such as at least one of nickel (Ni), copper (Cu), palladium (Pd), a palladium-silver (Pd-Ag) alloy, or the like. The conductive paste can be deposited using a printing method. For example, the printing method can be a screen printing method and / or a gravure printing method, but is not necessarily limited thereto, and any method for forming internal electrodes used in the art can be used. The internal electrode 12 can have a thickness of, for example, 100 nm to 5 μm, 100 nm to 2.5 μm, 100 nm to 1 μm, 100 nm to 800 nm, 100 nm to 400 nm, and / or 100 nm to 200 nm.

[0090] Reference Figure 6, a plurality of internal electrodes 12 alternately stacked so as to partially protrude from opposite side surfaces of the multilayer capacitor 1 may be electrically connected to an external electrode 13. The external electrode 13 may be, for example, on a laminate structure including dielectric material layers 11 alternately arranged between the plurality of internal electrodes 12, and connected to the internal electrodes 12. The multilayer capacitor 1 may include internal electrodes 12 and external electrodes 13 respectively connected to the internal electrodes 12. The multilayer capacitor 1 may include, for example, a pair of external electrodes 13 surrounding opposite sides of the laminate structure including the internal electrodes 12 and the dielectric material layers 11. The external electrode 13 may be any material having conductivity, such as a metal; or may be a specific material that may be determined in consideration of electrical characteristics, structural stability, and the like. The external electrode 13 may have, for example, a multilayer structure. The external electrode 13 may include, for example, an electrode layer contacting the laminate and the internal electrode 12 and including Ni, and a plating layer on the electrode layer.

[0091] Reference Figure 6 , the dielectric material layer 11 in the multilayer capacitor 1 may, for example, have a cross-sectional area larger than the cross-sectional area of the adjacent internal electrodes 12. The dielectric material layers 11 between adjacent internal electrodes 12 in the multilayer capacitor 1 may be connected to each other. The dielectric material layers 11 between adjacent internal electrodes 12 may be connected to each other at the side surfaces of the multilayer capacitor 1 and may be in contact with the external electrodes 13 in the multilayer capacitor 1. In some example embodiments, the external electrodes 13 may be omitted. When the external electrodes 13 are omitted, the internal electrodes 12 protruding to the opposite side of the multilayer capacitor 1 may be connected to a power source.

[0092] In a unit capacitor including adjacent internal electrodes 12 and a dielectric material layer 11 disposed therebetween, the thickness of the dielectric material layer 11 (e.g., the gap between adjacent internal electrodes 12) may be, for example, 10 nm to 1 μm, 100 nm to 800 nm, 100 nm to 600 nm, and / or 100 nm to 300 nm. In a unit capacitor including adjacent internal electrodes 12 and a dielectric material layer 11 therebetween, the dielectric constant of the dielectric material layer 11 may be, for example, 610 or greater within a range of 1 kHz to 1 MHz at room temperature (25° C.).

[0093] By including dielectric material layer 11 having such a small thickness and a high dielectric constant, multilayer capacitor 1 can have improved capacitance and reduced thickness and volume. Thus, a smaller, thinner capacitor with higher capacitance can be provided.

[0094] The dielectric material and / or the multilayer capacitor 1 including the dielectric material may be included in, for example, a semiconductor device D70. The semiconductor device D70 may have memory characteristics and may be, for example, a DRAM.

[0095] Figure 7AA circuit configuration of a memory cell of a memory device including a semiconductor device and a capacitor is described. Figure 7B is a schematic diagram showing a semiconductor device according to example embodiments.

[0096] Reference Figure 7A , the semiconductor device D70 may be included in a memory device as a memory cell, and may include a transistor D61 and a capacitor D60 electrically connected to, for example, a source region 730 of the transistor D61. The memory device may include a plurality of bit lines and a plurality of word lines, and may further include a plurality of memory cells. Each word line may be electrically connected to a gate electrode 710 of the transistor D61, and each bit line may be electrically connected to a drain region 720 of the transistor D61. The electrode of the capacitor D60 may be connected to, for example, a voltage controller (not shown). For example, referring to Figure 7B , the semiconductor device D70 may include: a capacitor D60 including a relaxor ferroelectric material 200; and a field effect transistor D61 electrically connected to the capacitor D60 via a contact 62. The capacitor D60 may be, for example Figure 6 Multilayer capacitor 1. One of the external electrodes 13 of capacitor D60 and one of the source region 730 and the drain region 720 of transistor D61 can be electrically connected through a contact 62. Contact 62 can include a conductive material such as tungsten, copper, aluminum, polysilicon, etc.

[0097] Field effect transistor D61 may include a substrate 780 including a source region 730, a drain region 720, and a channel 760, and a gate electrode 710 facing the channel 760. A dielectric layer 750 may be between the substrate 780 and the gate electrode 710. Figure 7B The field effect transistor D61 shows an example that does not include the relaxor ferroelectric material 200 , but the field effect transistor may also include the relaxor ferroelectric material 200 .

[0098] Hereinafter, a method of preparing a dielectric material according to one or more example embodiments will be described.

[0099] To prepare a dielectric material including the compound of Formula 1, first, a mixture of potassium salt, sodium salt, Nb compound, M-containing compound, A compound, and Sb compound may be mechanically ground. Subsequently, the ground product may be subjected to a first heat treatment under an oxidizing atmosphere.

[0100] [Formula 1]

[0101] (1-x)K a Na b NbO3·xM(A c Sb d )O3

[0102] As described above, in Formula 1, M may be a Group 2 element, A may be a trivalent element, 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1, and c + d = 1.

[0103] The potassium salt may be, for example, potassium carbonate, potassium sulfate, potassium nitrate (KNO3), or a combination thereof, and the sodium salt may be, for example, sodium carbonate, sodium sulfate, or a combination thereof. The Nb compound may be, for example, niobium oxide. The M-containing compound may be, for example, strontium carbonate, strontium sulfate, calcium carbonate, barium carbonate, magnesium carbonate, magnesium sulfate, calcium sulfate, barium sulfate, strontium oxide, magnesium oxide, or a combination thereof.

[0104] The A compound may be, for example, boron oxide, aluminum oxide (Al), gallium oxide (Ga), indium oxide (In), thallium oxide (Tl), scandium oxide (Sc), yttrium oxide (Y), lanthanum oxide (La), cerium oxide (Ce), praseodymium oxide (Pr), neodymium oxide (Nd), samarium oxide (Sm), europium oxide (Eu), gadolinium oxide (Gd), terbium oxide (Tb), dysprosium oxide (Dy), or a combination thereof. The antimony (Sb) compound may be, for example, antimony oxide.

[0105] The amounts of the potassium salt, sodium salt, Nb compound, M-containing compound, A compound, and Sb compound described above may be stoichiometrically controlled to obtain the compound of Formula 1.

[0106] In the preparation method according to one or more embodiments, mechanical grinding may be ball milling, jet milling, bead milling, roll milling, planetary milling, hand milling, high-energy ball milling, planetary ball milling, stirred ball milling, vibratory milling, mechanical fusion milling, shaker milling, grinder milling, disk milling, shaping milling, conical screw milling (e.g., using a Nauta type mixer), precision mixing (e.g., using a Nobilta mixer), high-speed mixing, and / or a combination thereof. Mechanical grinding may be, for example, wet grinding using a solvent. As described above, when mechanical grinding is performed according to the wet grinding described above, a dielectric material having improved dielectric constant characteristics may be prepared.

[0107] In wet grinding using a solvent, ethanol may be used as the solvent. Although the mechanical grinding time varies depending on the grinding conditions, the mechanical grinding time may be, for example, 1 to 30 hours, for example, 5 to 25 hours.

[0108] The first heat treatment may be performed at a temperature of 800 °C to 1000 °C, for example, 850 °C to 950 °C. The first heat treatment may be performed in an oxidizing atmosphere. The first heat treatment may be performed for, for example, 1 to 30 hours and / or 2 to 15 hours. By performing the heat treatment in an oxidizing atmosphere for such a period of time, the dielectric material may have further improved dielectric characteristics.

[0109] After the first heat treatment, a molded product can be obtained using the product from the first heat treatment, for example, by applying uniaxial pressure to the product of the first heat treatment.Then, the molded product can undergo a second heat treatment under an oxidizing atmosphere.

[0110] The second heat treatment may be performed at a temperature of 1100° C. to 1300° C., for example, 1150° C. to 1250° C. When the second heat treatment is performed under an oxidizing atmosphere, the second heat treatment may be performed for 1 to 30 hours and / or 3 to 25 hours. By further including the second heat treatment under such conditions, defects in the dielectric material can be effectively prevented.

[0111] The first heat treatment under oxidizing atmosphere and / or the second heat treatment can be carried out under the atmosphere comprising oxygen, carbon dioxide, air etc. In the atmosphere comprising oxygen, carbon dioxide, air etc., the amount of oxygen, carbon dioxide, air etc. can for example be 0.1 to 10 volume %, 0.1 to 5 volume %, 0.1 to 3 volume % and / or 0.5 to 2 volume % of total gas volume. The remaining gases except oxygen, carbon dioxide, air etc. can be inert gases. Inert gases can be argon, nitrogen etc., but are not limited thereto, and can be any inert gases used in this area. For example, the oxidizing gas comprising oxygen, carbon dioxide, air etc. can be mixed with inert gases to produce oxidizing atmosphere.

[0112] As used herein, an "oxidizing atmosphere" may also be, for example, an ambient air atmosphere.

[0113] The dielectric material according to one or more exemplary embodiments prepared by the above method may be a high dielectric material including quasi-cubic and polar nano-region (PNR) formations, which can be used in multilayer ceramic capacitors (MLCCs) in the trend of miniaturization and high performance. In addition, the dielectric material may be dense, having a relative density of 98% or higher.

[0114] The dielectric material according to one or more embodiments may be applicable as a multilayer dielectric for a piezoelectric actuator, a multilayer dielectric for an antenna, and / or a dielectric for a non-volatile memory device. The dielectric material may be implemented as an MLCC in an electronic device, such as a mobile phone, a television, and / or a vehicle.

[0115] One or more embodiments of the present disclosure will now be described in detail with reference to the following examples and comparative examples.

[0116] (Preparation of Dielectric Materials)

[0117] Example 1

[0118] K2CO3, Na2CO3, Nb2O5, SrCO3, Ga2O3, and Sb2O3 were mixed to obtain a mixture, to which ethanol and zirconium oxide balls were added. The resulting mixture was then ball-milled in an air atmosphere at room temperature for 24 hours to prepare a mixture. The prepared mixture was dried at 100°C for one day to obtain a dry powder. Here, the amounts of K2CO3, Na2CO3, Nb2O5, SrCO3, Ga2O3, and Sb2O3 were controlled to be stoichiometric to obtain the dielectric material shown in Table 1.

[0119] The dried powder was placed in an alumina crucible and then subjected to a first heat treatment at 950° C. for 12 hours in an air atmosphere.

[0120] The first heat-treated product was pressed with a uniaxial press to prepare a pellet. The prepared pellet was heat-treated at 1250° C. for 24 hours in an air atmosphere to prepare a dielectric material having the composition shown in Table 1 below.

[0121] Example 2

[0122] A dielectric material was prepared in the same manner as in Example 1, except that Sc 2 O 3 was used instead of Ga 2 O 3 .

[0123] Example 3

[0124] A dielectric material was prepared in the same manner as in Example 1, except that La 2 O 3 was used instead of Ga 2 O 3 .

[0125] Example 4

[0126] The dielectric material was prepared in the same manner as in Example 1, except that the amounts of K 2 CO 3 , Na 2 CO 3 , Nb 2 O 5 , SrCO 3 , Ga 2 O 3 , and Sb 2 O 3 were stoichiometrically controlled to obtain the dielectric material as shown in Table 1.

[0127] Example 5

[0128] A dielectric material was prepared in the same manner as in Example 1, except that Sc2O3 was used instead of Ga2O3, and the amounts of K2CO3, Na2CO3, Nb2O5, SrCO3, Sc2O3, and Sb2O3 were stoichiometrically controlled to obtain the dielectric material shown in Table 1.

[0129] Example 6

[0130] A dielectric material was prepared in the same manner as in Example 1, except that La2O3 was used instead of Ga2O3, and the amounts of K2CO3, Na2CO3, Nb2O5, SrCO3, La2O3, and Sb2O3 were stoichiometrically controlled to obtain the dielectric material shown in Table 1.

[0131] Examples 7-8

[0132] The dielectric material was prepared in the same manner as in Example 1, except that the amounts of K 2 CO 3 , Na 2 CO 3 , Nb 2 O 5 , SrCO 3 , Ga 2 O 3 , and Sb 2 O 3 were controlled to be stoichiometric to obtain the dielectric material as shown in Table 1.

[0133] Examples 9-10

[0134] The dielectric material was prepared in the same manner as in Example 1, except that Sc2O3 was used instead of Ga2O3, and the amounts of K2CO3, Na2CO3, Nb2O5, SrCO3, Sc2O3, and Sb2O3 were controlled to be stoichiometric to obtain the dielectric material shown in Table 1.

[0135] Examples 11-12

[0136] The dielectric material was prepared in the same manner as in Example 1, except that La2O3 was used instead of Ga2O3, and the amounts of K2CO3, Na2CO3, Nb2O5, SrCO3, La2O3, and Sb2O3 were controlled to be stoichiometric to obtain the dielectric material shown in Table 1.

[0137] Comparative Example 1

[0138] The dielectric material (K 0.5 Na 0.5 )NbO3(KNN), except that: no SrCO3, Ga2O3, and Sb2O3 are added.

[0139] [Table 1]

[0140] Example Composition of dielectric materials Example 1 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.925K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.075Sr(Ga<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 2 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.925K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.075Sr(Sc<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 3 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.925K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.075Sr(La<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 4 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.9K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.1Sr(Ga<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 5 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.9K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.1Sr(Sc<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 6 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.9K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.1Sr(La<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 7 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.99K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.01Sr(Ga<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 8 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.7K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.3Sr(Ga<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 9 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.99K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.01Sr(Sc<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 10 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.7K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.3Sr(Sc<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 11 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.99K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.01Sr(La<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Example 12 <h2 style=";text-align:left;direction:ltr"><![CDATA[0.7K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3·0.3Sr(La<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Sb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> )O3]]><h2 style=";text-align:left;direction:ltr"> Comparative Example 1 <h2 style=";text-align:left;direction:ltr"><![CDATA[K <h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Nb<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> O3]]><h2 style=";text-align:left;direction:ltr">

[0141] Evaluation Example 1: X-ray diffraction experiment

[0142] The powder X-ray diffraction (XRD) spectra of the dielectric materials of Comparative Example 1, Example 1 and Example 4 were measured using CuKα radiation. Powders obtained by grinding a sheet of each dielectric material were used, and a Bruker D8 Advance was used for the XRD analysis. The measurement results are shown in FIG. Figure 3A middle. Figure 3B yes Figure 3A Magnified view of the rectangular area (which is the area at 2θ of 44 to 47°).

[0143] like Figure 3A As shown in , the dielectric materials of Examples 1 and 4 have substantially the same peak positions as the dielectric material of Comparative Example 1.

[0144] As shown, the dielectric materials of Examples 1 and 4 exhibited a main peak including a broad single peak in the diffraction angle (2θ) region of 45 to 47°. From these results, it was found that the dielectric materials of Examples 1 and 4 had a composite phase crystal structure, for example, a pseudo-cubic phase crystal structure including at least one selected from an orthorhombic phase and a cubic phase.

[0145] In contrast, the dielectric material of Comparative Example 1 shows peaks related to the (022) plane and the (200) plane in the 2θ region of 44 to 47°, as shown in Figure 3B As can be seen from the results, it is shown that the dielectric material has an orthorhombic crystal structure. In addition, the dielectric material of Comparative Example 1 shows a peak at a different position from the dielectric materials of Examples 1 and 4, and a different peak shape. From these results, it was found that the dielectric materials of Examples 1 and 4 include a phase having a different crystal structure from the dielectric material of Comparative Example 1.

[0146] Evaluation Example 2: Temperature Characteristics of Dielectric Constant

[0147] Silver (Ag) electrodes were coated on opposite surfaces of the sheets of dielectric materials prepared in Example 1, Example 4, and Comparative Example 1 to prepare samples. The dielectric constant of each sample was measured using an LCR meter (Agilent, E4980A) at 25°C and 1 kHz / 1.0 V. The dielectric constant was measured in a temperature-controlled chamber at intervals of 5°C at temperatures ranging from -55°C to 200°C with reference to EIA specification X7S, and the results are shown in FIG. Figure 4 middle.

[0148] Reference Figure 4 Although not shown, the dielectric material of Comparative Example 1 has a cubic transition temperature of 400° C. and exhibits a maximum dielectric constant at this temperature. As used herein, “cubic transition temperature” refers to a temperature at which the dielectric material of Comparative Example 1 having an orthorhombic crystal structure changes to a cubic phase at room temperature.

[0149] However, the dielectric materials of Examples 1 and 4 exhibited maximum dielectric constants at 80° C. and 0° C., respectively. This indicates that the dielectric materials of Examples 1 and 4 have stable temperature characteristics of dielectric constants and become quasi-cubic at room temperature (25° C.).

[0150] In order to determine the temperature characteristics of dielectric constant, such as the temperature coefficient of capacitance (TCC), the dielectric constant was measured in a temperature-controlled chamber at intervals of 5°C at temperatures from -55°C to 200°C with reference to EIA specification X7S, and some of the results are shown in Table 2.

[0151] The temperature characteristic of the dielectric constant is expressed by Equation 1. The temperature characteristic of the dielectric constant is obtained by measuring capacitance according to temperature.

[0152] <Equation 1>

[0153] TCC (%) = [(capacitance at 125°C - capacitance at 25°C) / capacitance at 25°C] × 100

[0154] [Table 2]

[0155] Example composition TCC (%) Example 1 0.925KNN·0.075SGS 5 Example 4 0.9KNN·0.1SGS -16 Comparative Example 1 KNN 37

[0156] As shown in Table 2, the dielectric materials of Examples 1 and 4 exhibited a change in capacitance ranging from -16% to 5% within the temperature range of 25°C to 125°C.

[0157] Therefore, the dielectric materials of Examples 1 and 4 exhibit stable temperature characteristics of dielectric constants.

[0158] In contrast, the dielectric material of Comparative Example 1 exhibited poor temperature characteristics of the dielectric constant.

[0159] Evaluation Example 3: Measurement of specific resistance and dielectric properties

[0160] The density, specific resistance, and dielectric properties of the dielectric materials of Examples 1 to 6 and Comparative Example 1 were evaluated according to the following methods.

[0161] (1) Specific resistance

[0162] Using a Premier II Ferroelectric Tester (Radiant Technologies, Inc.), the specific resistance was measured for 1 second after stabilization for 60 seconds under conditions of applying a DC high electric field of 8.7 V / μm.

[0163] (2) Nominal dielectric constant

[0164] Silver (Ag) was coated on opposite surfaces of the dielectric sheet to form opposing electrodes, and then the dielectric constant was measured using an E4980A Precision LCR Meter (Keysight) at room temperature at 1 V and AC frequency of 100 Hz, 1 kHz, or 100 MHz.

[0165] (3) Dielectric constant reduction rate (effective dielectric constant: ε dc )

[0166] The dielectric constant reduction rate (e.g., effective permittivity (ε)) was evaluated using a Premier II Ferroelectric Tester (Radiant Technologies, Inc.) under conditions of applying a DC electric field (0 V / μm or 8.7 V / μm) and an AC electric field (87 mV / μm) at a frequency of 100 Hz. dc )). The effective permittivity is expressed by Equation 2.

[0167] [Equation 2]

[0168] Δε / ε0=(ε-ε0) / ε0

[0169] In Equation 2, ε represents a dielectric constant (eg, an effective dielectric constant) at dc=8.7 V / μm, and ε0 represents a dielectric constant at dc=0 V / μm.

[0170] The evaluation results of specific resistance, nominal dielectric constant, and effective permittivity are shown in Table 3.

[0171] [Table 3]

[0172]

[0173] The densities in Table 3 are relative densities, which were measured by using a buoyancy method (ie, Archimedes' method).

[0174] In Table 3, ε represents the dielectric constant, and tanδ represents the loss factor.

[0175] As shown in Table 3, the dielectric materials of Examples 1 to 3 had a nominal dielectric constant of 1,700 or greater, compared to the dielectric material of Comparative Example 1 having a nominal dielectric constant of 608. The specific resistance of the dielectric materials of Examples 1 to 6 under the condition of applying a high electric field of 8.7 V / μm was higher than that of Comparative Example 1.

[0176] The dielectric material of Comparative Example 1 exhibited a dielectric constant reduction rate (effective permittivity: ε dc ), while those of Examples 1 to 6 exhibited greatly enhanced dielectric constants, indicating improved dielectric constant characteristics.

[0177] Figure 5 Changes in polarization according to an electric field in the dielectric materials of Example 1, Example 4, and Comparative Example 1 are described.

[0178] refer to Figure 5 , the dielectric material of Comparative Example 1 exhibits a change in polarization of the ferroelectric, and the dielectric material of Example 4 exhibits a change in polarization of the phase dielectric.

[0179] The dielectric material of Example 1 has an increased content of KNN compared to the dielectric material of Example 4. It can be seen that as the content of KNN increases, the structure of the dielectric material changes from an orthorhombic structure of KNN (ferroelectric) to a quasi-cubic structure (phase dielectric).

[0180] According to one or more exemplary embodiments, a device having improved dielectric constant characteristics is provided by including a dielectric material having improved structural stability and physical properties according to one or more embodiments. The dielectric material effectively operates in a high electric field range, and thus, a device having high efficiency can be manufactured as the dielectric material layer becomes thinner.

[0181] It should be understood that the example embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. The description of features and / or aspects in each embodiment should typically be considered to be applicable to other similar features and / or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope defined by the appended claims.

Claims

1. A dielectric material comprising a compound represented by Formula 1: [Formula 1] (1-x)K a And b NbO3·xM(A c Sb d )O3 in, In Formula 1, K is potassium, Na is sodium, Nb is niobium, Sb is antimony, O is oxygen, M is a Group 2 element, A is a trivalent element, and 0 < x < 1, 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, a + b = 1 and c + d = 1.

2. The dielectric material according to claim 1, wherein M is strontium (Sr), calcium (Ca), barium (Ba), magnesium (Mg), or a combination thereof.

3. The dielectric material according to claim 1, wherein A is boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), or a combination thereof.

4. The dielectric material according to claim 1, wherein the compound represented by Formula 1 is a compound represented by Formula 2: [Formula 2] (1-x)K a No b NbO3·xSr(A c Sp d )O3 in, In Formula 2, A is boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), or a combination thereof.

5. The dielectric material according to claim 1 or 4, wherein x is from 0.01 to 0.

3.

6. The dielectric material according to claim 1 or 4, wherein x is from 0.05 to 0.

2.

7. The dielectric material according to claim 1, wherein the compound represented by Formula 1 is a compound represented by Formula 3: [Formula 3] (1-x)K a No b NbO3·xSr(B c Sp d )O3; wherein the compound represented by Formula 1 is a compound represented by Formula 4: [Formula 4] (1-x)K a And b NbO3·xSr(Ga c Sb d )O3: wherein the compound represented by Formula 1 is a compound represented by Formula 5: [Formula 5] (1-x)K a Na b NbO3·xSr(Sc c Sb d )O3; or wherein the compound represented by Formula 1 is a compound represented by Formula 6: [Formula 6] (1-x)K a And b NbO3·xSr(La c Sb d )O3。 8. The dielectric material according to claim 1, wherein the compound represented by Formula 1 exhibits a main peak including a single - peak form in the diffraction angle (2θ) region of 45° to 47°, as obtained by X - ray diffraction analysis.

9. The dielectric material according to claim 1, wherein the compound represented by Formula 1 comprises a composite - phase crystal structure, the composite - phase crystal structure comprising one or more selected from orthorhombic, cubic, and tetragonal crystal structures.

10. The dielectric material according to claim 9, wherein the composite - phase crystal structure comprises a quasi - cubic crystal structure.

11. The dielectric material according to claim 1, wherein the electric - field - polarization plot for the compound represented by Formula 1 shows a linear curve proportional to the electric field, wherein the maximum polarization and polarization decrease as x increases.

12. The dielectric material according to claim 1, wherein the compound represented by Formula 1 is at least one of the following: (1-x)(K a Na b )NbO3·xSr(Ga c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(Sc c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(La c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(B c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(Al c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(In c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(Y c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(Ce c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(Nd c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(Gd c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(Sm c Sb d )O3、(1-x)(K a Na b )NbO3·xSr(Eu c Sb d )O3、(1-x)(K a And b )NbO3·xSr(Tb c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Ga c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Sc c Sb d )O3、(1-x)(K a And b )NbO3·xCa(La c Sb d )O3、(1-x)(K a And b )NbO3·xCa(B c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Al c Sb d )O3、(1-x)(K a And b )NbO3·xCa(In c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Y c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Ce c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Nd c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Gd c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Sm c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Eu c Sb d )O3、(1-x)(K a And b )NbO3·xCa(Tb c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Ga c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Sc c Sb d )O3、(1-x)(K a And b )NbO3·xBa(La c Sb d )O3、(1-x)(K a And b )NbO3·xBa(B c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Al c Sb d )O3、(1-x)(K a And b )NbO3·xBa(In c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Y c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Ce c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Nd c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Gd c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Sm c Sb d )O3、(1-x)(K a And b )NbO3·xBa(Eu c Sb d )O3, sum(1-x)(K a Na b )NbO3·xBa(Tb c Sb d )O3, in, In Formula 1, x is 0.01 to 0.3, a and b are each independently 0.4 to 0.6, c and d are each independently 0.4 to 0.6, the sum of a and b is 1, and the sum of c and d is 1.

13. The dielectric material according to claim 1, wherein the compound represented by Formula 1 is at least one of the following: (1-x)(K 0.5 Na 0.5 )NbO3·xSr(Ga 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(Sc 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(La 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(B 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(Al 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(In 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(Y 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(Ce 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(Nd 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(Gd 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(Sm 0.5 Sb 0.5 )O3、(1-x)(K 0.5 Na 0.5 )NbO3·xSr(Eu 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xSr(Tb 0.5 Sb 0.5 )O3(1-x)(K 0.5 And 0.5 )NbO3·xCa(Ga 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Sc 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(La 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(B 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Al 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(In 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Y 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Ce 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Nd 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Gd 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Sm 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Eu 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xCa(Tb 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(Ga 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(Sc 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(La 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(B 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(Al 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(In 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(Y 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(Ce 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(Nd 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(Gd 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(Sm 0.5 Sb 0.5 )O3、(1-x)(K 0.5 And 0.5 )NbO3·xBa(Eu 0.5 Sb 0.5 )O3, sum(1-x)(K 0.5 Na 0.5 )NbO3·xBa(Tb 0.5 Sb 0.5 )O3, in, x is 0.01 to 0.

3. 14 . The dielectric material of claim 1 , wherein the compound represented by Formula 1 has a dielectric constant of 610 or more at 1 kHz to 1 MHz.

15. The dielectric material according to claim 1, wherein In the compound represented by Formula 1, (1-x)K a Na b NbO3 and xM(A c Sb d )O3 forms a solid solution.

16. Devices, including: Multiple electrodes; and a layer of dielectric material between the plurality of electrodes, The dielectric material layer comprises the dielectric material according to any one of claims 1 to 15.

17. The device of claim 16, wherein the device is a capacitor.

18. The device of claim 16, wherein the dielectric material layer between the plurality of electrodes has a thickness of 1000 nm or less.

19. The device of claim 16, wherein the device is a multilayer capacitor comprising: multiple internal electrodes; and dielectric material layers alternately disposed between the plurality of internal electrodes.

20. The device of claim 16, wherein the dielectric material layer has a dielectric constant of 610 or higher at 1 kHz to 1 MHz.

21. The device of claim 16, wherein the dielectric material layer has a specific resistance of 1.0E+9 Ωcm or greater.

22. A memory unit comprising: transistor; and capacitors, At least one of the transistor and the capacitor comprises a device according to any one of claims 16 to 21.

23. A method for preparing the dielectric material according to any one of claims 1 to 15, the method comprising: Mechanically grinding a mixture of potassium (K) salt, sodium (Na) salt, niobium (Nb) compound, M-containing compound, A compound and antimony compound; and The first heat treatment is performed in an oxidizing atmosphere.

24. The method of claim 23, wherein the first heat treatment is performed at a temperature of 800°C to 1000°C.

25. The method according to claim 24, further comprising, after performing the first heat treatment in an oxidizing atmosphere: obtaining a molded body using the product of the first heat treatment; and The molded body is subjected to a second heat treatment.

26. The method of claim 25, wherein obtaining the molded body comprises applying uniaxial pressure to the product of the first heat treatment.

27. The method of claim 25, wherein the second heat treatment is performed at a temperature of 1,100°C to 1,300°C.

28. The method of claim 23, wherein the potassium salt is potassium carbonate, potassium sulfate, potassium nitrate, or a combination thereof, The sodium salt is sodium carbonate, sodium sulfate or a combination thereof, The Nb compound is niobium oxide, The compound containing M is strontium carbonate, strontium sulfate, calcium carbonate, barium carbonate, magnesium carbonate, magnesium sulfate, calcium sulfate, barium sulfate, strontium oxide, magnesium oxide or a combination thereof, The compound A is boron oxide, aluminum oxide (Al), gallium oxide (Ga), indium oxide (In), thallium oxide (Tl), scandium oxide (Sc), yttrium oxide (Y), lanthanum oxide (La), cerium oxide (Ce), praseodymium oxide (Pr), neodymium oxide (Nd), samarium oxide (Sm), europium oxide (Eu), gadolinium oxide (Gd), terbium oxide (Tb), dysprosium oxide (Dy) or a combination thereof, and The antimony compound is antimony oxide.

29. The method of claim 23, wherein the mechanical milling is ball milling, air jet milling, bead milling, roller milling, planetary milling, hand milling, vibratory milling, mechanical fusion milling, shaker milling, attritor milling, disc milling, profile milling, conical screw milling, or a combination thereof.

30. The method of claim 23, wherein the mechanical milling is high energy ball milling, planetary ball milling, stirred ball milling, or a combination thereof.

31. The method of claim 23, wherein the mechanical milling comprises wet milling using a solvent.

32. The method of claim 31 , wherein the solvent comprises ethanol.

33. The method of claim 23, wherein the oxidizing atmosphere is an air atmosphere; or The oxidizing atmosphere comprises 0.1 to 10% oxygen, carbon dioxide, air or a combination thereof, and The remainder of the oxidizing atmosphere comprises an inert gas.

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