Ceramic, and filler or capacitor including the ceramic

Abstract

To provide ceramic usable as a dielectric, having a high dielectric constant and showing a low rate of change in a temperature range of not higher than 200°C, and having a small mean coefficient of linear expansion.SOLUTION: The ceramic for solving the above problems, is characterized by containing, in terms of mol%, 82.0 to 96.0% of a Nb2O5 component, 3.0 to 15.0% of (P2O5 + GeO2), and more than 0.0 and not more than 5.0% of (SiO2+MnO2) relative to the total amount of substances of a composition in terms of oxides, and having a dielectric constant of not lower than 600, a dielectric loss of not more than 5.0% at a 1 kHz frequency at a temperature of 25°C, and a mean coefficient of linear expansion of not higher than 50×10-7 / K at a temperature of from -30 to 70°C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to ceramics having properties that allow them to be used as dielectrics, and more specifically to ceramics that have a high dielectric constant in the temperature range of 25°C to 200°C, a small change in the dielectric constant with temperature, and a small average linear expansion coefficient, as well as fillers or capacitors containing such ceramics. [Background technology]

[0002] As electronic devices such as smartphones and tablets become more widespread, there is a demand for smaller, more powerful electronic components to be used in these devices. Naturally, there is also a demand for multilayer ceramic capacitors (MLCCs) to be smaller and have higher capacitance.

[0003] In recent years, with the spread of electric vehicles, there has been a demand for mounting electrical circuit boards directly around the motor, which becomes hot, in order to improve motor performance and make the motor more compact.However, as the temperature of the operating environment for on-board electrical components rises, MLCCs are also required to have high capacitance and good capacitance-temperature characteristics even at higher temperatures.In other words, the dielectric that makes up the capacitor must have a high dielectric constant even in the high-temperature range of 200°C, and the dielectric constant must vary little with temperature.

[0004] Furthermore, in recent years, there has been an increasing demand for capacitors with high energy storage density for use in excimer lasers used in semiconductor processing and vision correction surgery, medical X-rays, power storage devices, power transmission facilities, etc. The dielectrics used in such capacitors are required to have both a high dielectric constant and a small average linear expansion coefficient to achieve high energy storage density, and also to have little change in capacitance with temperature even at high temperatures.

[0005] However, BaTiO3, which is widely used as a dielectric, has a Curie temperature of around 130°C, so the dielectric constant drops significantly in the temperature range above 150°C, making it unable to satisfy the above requirements.

[0006] Furthermore, Patent Document 1 describes that the Curie temperature can be increased in a BaTiO3 composite oxide, and that good temperature characteristics of capacitance can be obtained up to 200°C. However, this dielectric material has the drawback of having a dielectric constant of 500 or less, making it impossible to obtain a large capacitance.

[0007] Furthermore, when the dielectric material having a high average linear expansion coefficient is applied to a ceramic electronic component such as a capacitor, there is a problem that the structure around the external electrodes is warped due to thermal expansion, which tends to cause cracks in the element body constituting the laminate. Therefore, a smaller average linear expansion coefficient is required for the dielectric material. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2017-119607 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to solve the above-mentioned problems, that is, to provide ceramics that can be used as a dielectric, have a high dielectric constant in a temperature range of 200°C or less, a small change in the dielectric constant with temperature, and a small average linear expansion coefficient. [Means for solving the problem]

[0010] In order to solve the above problems, the present inventors have conducted extensive research and have found that the composition of the composite oxides contains, in mole percent, 82.0 to 96.0% of Nb2O5, 3.0 to 15.0% of (P2O5 + GeO2), and more than 0.0% and 5.0% or less of (SiO2 + MnO2), and the composite oxides have a dielectric constant of 600 or more and a dielectric loss of 5.0% or less at a frequency of 1 kHz at 25°C, and an average linear expansion coefficient of 50 x 10 -7 / K or less can solve the above problems, and this led to the completion of the present invention. The present invention is as follows: <1> ~ <8> is. <1> The material contains, in mole percent, 82.0 to 96.0% of Nb2O5, 3.0 to 15.0% of (P2O5 + GeO2), and more than 0.0% but not more than 5.0% of (SiO2 + MnO2) relative to the total amount of substance in the oxide-equivalent composition, and has a dielectric constant of 600 or more and a dielectric loss of 5.0% or less at a frequency of 1 kHz at 25°C, and an average linear expansion coefficient of 50 x 10 -7 / K or less. <2> The above-mentioned dielectric constant has a temperature coefficient of change of 30% or less in the range of 25°C to 200°C and at frequencies of 100 Hz to 100 kHz. <1> The ceramics described in <3> The above-mentioned composition characterized in that Nb2O5 / (P2O5+GeO2) is 7.0 to 20.0 <1> or <2> The ceramics described in <4> As a crystalline phase, PNb9O 25 , GeNbO 25 , GeNb 18 O 47 and solid solutions thereof. <1> ~ <3> The ceramic according to any one of the preceding items. <5> the above <1> ~ <4> A dielectric comprising the ceramic material according to any one of the preceding claims. <6> the above <5> A capacitor comprising the dielectric material according to claim 1. <7> the above <1> ~ <4> A filler material comprising the ceramic material according to any one of the above items. <8> the above <7> A capacitor comprising the filler material according to claim 1. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a dielectric having a high dielectric constant and excellent temperature characteristics in the temperature range of 25° C. to 200° C., as well as a filler material and a capacitor containing the dielectric. [Brief explanation of the drawings]

[0012] [Figure 1] 1 shows the frequency dependence of the dielectric constant of Example 1 and Comparative Example 1 at room temperature (25° C.). [Figure 2] 1 shows the dielectric constant and dielectric loss of Example 1 at 1 kHz in the temperature range from room temperature (25° C.) to 200° C. [Figure 3] 1 shows the temperature coefficient of change (εT) of the dielectric constant of Example 1 in the temperature range from room temperature (25°C) to 200°C. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Ceramics of the present invention> The ceramic of the present invention will now be described. The present invention relates to a ceramic sintered body containing, in mole percent relative to the total amount of substances in the oxide-equivalent composition, 82.0 to 96.0% of an Nb2O5 component, 3.0 to 15.0% of (P2O5 + GeO2), and more than 0.0% and 5.0% or less of (SiO2 + MnO2), and the ceramic sintered body has a dielectric constant of 600 or more and a dielectric loss of 5.0% or less at a frequency of 1 kHz at 25°C, and an average linear expansion coefficient of 50 x 10 -7 / K or less. The ceramics are useful as dielectrics, fillers, and capacitors.

[0014] Unless otherwise specified, the contents of the constituent components contained in the ceramic of the present invention are all expressed in mole percent relative to the total amount of substances in the composition converted into oxides. The content expressed as "mol percent relative to the total amount of substances in the composition converted into oxides" refers to the content of each component contained in the ceramic of the present invention, assuming that the oxides, composite salts, metal fluorides, etc. used as raw materials for the ceramic of the present invention are all decomposed and converted into oxides during melting, with the total number of moles (total amount of substances) of the generated oxides being 100 mole percent.

[0015] <Components> First, each component constituting the ceramic of the present invention will be described.

[0016] The Nb2O5 component is an essential component necessary to achieve the object of the present invention. To obtain a high dielectric constant, the lower limit of the Nb2O5 component content is preferably 82.0% or more, more preferably 83.0% or more, even more preferably 86.0% or more, even more preferably 87.0% or more, and even more preferably 88.0% or more. For the same reasons, the upper limit is preferably 96.0% or less, more preferably 95.0% or less, even more preferably 93.0% or less, even more preferably 91.0% or less, and even more preferably 90.0% or less.

[0017] The P2O5 and GeO2 components form an oxide crystalline phase with the Nb2O5 component described above in the ceramics of the present invention, and are essential components for achieving excellent dielectric properties. Therefore, at least one of these components must be present. When the P2O5 component is present alone, its content is preferably 15.0% or less, more preferably 12.0% or less, and even more preferably 10.0% or less. When the GeO2 component is present alone, its content is preferably 15.0% or less, more preferably 12.5% ​​or less, and even more preferably 10.5% or less. Furthermore, even when both components are present simultaneously, the total amount (P2O5 + GeO2) is preferably in the range of 3.0 to 15.0%, with the lower limit of this total amount being preferably 5.0% or more, more preferably 7.0% or more, even more preferably 8.5% or more, and even more preferably 9.0% or more. Of these, the content of the P2O5 component is preferably 3.0% or more, and even more preferably 5.0% or more. The upper limit of the total amount is more preferably 13.5% or less, even more preferably 12.5% ​​or less, and even more preferably 11.0% or less. Among these, the content of the GeO2 component is more preferably 10.0% or less, even more preferably 8.0% or less, and even more preferably 6.0% or less. In order to more easily achieve the effects of the present invention, the ratio of the content of the Nb2O5 component to the total amount (P2O5 + GeO2), i.e., Nb2O5 / (P2O5 + GeO2), is preferably in the range of 7.0 to 20.0, and the lower limit of this ratio is more preferably 7.1 or more, even more preferably 7.2 or more, even more preferably 7.5 or more, even more preferably 8.0 or more, and still more preferably 8.5 or more. The upper limit of this ratio is more preferably 15.0 or less, even more preferably 13.0 or less, even more preferably 11.0 or less, even more preferably 10.0 or less, and still more preferably 9.5 or less.

[0018] By using the above composition, the ceramic of the present invention can be obtained as PNbO 25 , GeNbO 25 , GeNb 18 O 47, and one or more crystal phases selected from the group consisting of these solid solutions are easily formed. Here, this "solid solution" refers to a solid (crystalline solid) in which a crystal phase and other elements are mutually dissolved to form a uniform solid phase. The solid solution here can be expressed by the formula (P 1-x , Ge x )Nb9O 25 (0 < x < 1) and / or (Ge 1-y , P y )Nb 18 O 47 (0 < y < 1). However, in order to obtain a stable solid solution, it is preferable that both x and y are 0.8 or less, more preferably 0.6 or less, and even more preferably 0.5 or less. Due to the presence of these crystals or solid solutions, excellent dielectric properties can be obtained. Furthermore, it is more preferable that these crystal phases are contained in the ceramics of the present invention in a total amount of more than 50 mol%, even more preferably 60 mol% or more, and even more preferably 70 mol% or more. That is, it is preferable that these crystal phases are the main crystal phases. In addition, this crystal phase can be determined and measured by analyzing the XRD pattern obtained by the X-ray diffraction (XRD) method using an X-ray diffractometer (for example, D8 DISCOVER manufactured by Bruker) (for example, separating diffraction peaks from each other after function fitting of diffraction peaks and analyzing the area ratio thereof, or analysis by the Rietveld method, etc.).

[0019] Furthermore, the SiO2 and MnO2 components lower the sintering temperature of ceramics, improve sintered density, and dissolve in the aforementioned crystals or solid solutions to enhance dielectric properties. Therefore, at least one of these components must be present. While these components may be added alone, adding them together provides greater benefits. The total amount of both components (SiO2 + MnO2) is preferably greater than 0.0% and less than 5.0%, with the lower limit of this total amount being more preferably 0.1% or greater, even more preferably 0.2% or greater, and even more preferably 0.4% or greater. Of these, the SiO2 content is preferably greater than 0.0%, even more preferably 0.1% or greater, and even more preferably 0.2% or greater. The upper limit of the total amount is more preferably 4.0% or less, even more preferably 3.0% or less, even more preferably 2.0% or less, even more preferably 1.5% or less, and even more preferably 1.0% or less. Of these, the MnO2 content is preferably 0.5% or less, even more preferably 0.3% or less.

[0020] In addition to the above, the ceramics of the present invention may contain B2O3, Al2O3, ZnO, Bi2O3, TiO2, ZrO2, Ta2O5, WO3, alkali metal oxides, alkaline earth metal oxides, rare earth oxides, transition metal oxides, fluorides, etc. These components function as sintering aids and may exist alone, be solid-solubilized in the above-mentioned crystalline phases, or form new crystals with elements constituting the above-mentioned crystals. The incorporation of these components can improve dielectric properties by lowering the firing temperature or forming solid solutions. The total content of these components is preferably 10% or less, more preferably 5% or less, and most preferably 3% or less.

[0021] The ceramic of the present invention may contain glass. Glass acts as a sintering aid and has the effect of lowering the firing temperature. In other words, the ceramic of the present invention may contain amorphous glass in part, but the proportion is preferably 10 mol % or less, more preferably 5 mol % or less, even more preferably 1 mol % or less, and even more preferably 0.1 mol % or less (substantially no glass is contained).

[0022] The ceramics of the present invention can be composited with other dielectric crystals, such as tungsten bronze crystals, perovskite crystals, CaZrO3 crystals, SrZrO3 crystals, BaTi2O5 crystals, CaTi2O5 crystals, etc. By combining with these dielectrics, it is possible to achieve dielectric properties closer to those designed. The above-mentioned tungsten bronze crystals include MNb2O6 (M: Ca, Sr, Ba), MNb5O 15 (M:Ca, Sr, Ba; R:Na, K), K2LnNb5O 15 Preferred examples include one or more selected from the group consisting of (Ln:Y, Ce, Sm, Eu, La, Gd, Tb, Dy, Ho, Bi) crystals and solid solutions thereof. The perovskite type includes RNbO3, RTaO3, (Bi 0.5 ,R 0.5 Preferred examples include at least one selected from the group consisting of TiO3 (R: Na, K), MTiO3 (M: Ca, Sr, Ba) crystals, and solid solutions thereof.

[0023] The ceramic of the present invention preferably has a dielectric constant of 600 or more at a frequency of 1 kHz at room temperature (25°C), more preferably 800 or more, even more preferably 900 or more, even more preferably 1000 or more, and even more preferably 1100 or more. Furthermore, in the frequency range of 100 Hz to 100 kHz at room temperature (25°C), the dielectric constant is more preferably 600 or more, even more preferably 800 or more, even more preferably 900 or more, even more preferably 1000 or more, and even more preferably 1100 or more. In addition, the dielectric constant at a frequency of 1 kHz in the range of room temperature (25°C) to 200°C is preferably 600 or more, more preferably 800 or more, even more preferably 900 or more, and even more preferably 1000 or more. Furthermore, the dielectric loss at a frequency of 1 kHz at room temperature (25°C) is preferably 5% or less, more preferably 3% or less, even more preferably 2% or less, even more preferably 1.5% or less, and even more preferably 1.0% or less. In addition, the dielectric loss at a frequency of 1 kHz in the range of room temperature (25°C) to 200°C is preferably 5% or less, more preferably 3% or less, even more preferably 2% or less, even more preferably 1.5% or less, and even more preferably 1.0% or less. Here, the dielectric constant and dielectric loss are both values ​​measured by an impedance analyzer (for example, SI1260 manufactured by Solartron or E4990A manufactured by Keysight).

[0024] Furthermore, the ceramic of the present invention preferably has a dielectric constant of 600 or more and a temperature coefficient of the dielectric constant of 30% or less at a frequency of 1 kHz in a temperature range of 200°C or less (temperature range of 25°C to 200°C), more preferably a dielectric constant of 800 or more and a temperature coefficient of the dielectric constant of 25% or less, even more preferably a dielectric constant of 900 or more and a temperature coefficient of the dielectric constant of 25% or less, and even more preferably a dielectric constant of 1000 or more and a temperature coefficient of the dielectric constant of 25% or less.It is further preferable that the dielectric constant and the temperature coefficient of the dielectric constant at a frequency of 100 Hz to 100 kHz in a temperature range of 200°C or less (temperature range of 25°C to 200°C) are also within the above ranges. Here, the temperature change rate of this dielectric constant (ε T ) is the rate of change of the dielectric constant at each temperature when the dielectric constant at 25°C (dielectric constant at a specified frequency) is used as the reference, and is calculated using the following formula (1). (1) ε T (%) = [(dielectric constant at each temperature - dielectric constant at 25°C) / dielectric constant at 25°C] x 100%

[0025] The ceramic of the present invention has an average linear expansion coefficient of 50×10 at temperatures between −30°C and 70°C. -7 / K or less, and 40 × 10 -7 / K or less is more preferable, and 30×10 -7 / K or less is more preferable, and 20×10 -7 It is more preferable that the temperature is 1 / K or less. Here, this average coefficient of linear expansion (CTE) is a value measured using, for example, a TD5000S manufactured by Mac Science, with reference to the Japan Optical Glass Industry Association standard JOGIS-16 (2019) "Method for measuring the average coefficient of linear expansion of optical glass near room temperature."

[0026] The ceramics of the present invention have a high dielectric constant over a wide temperature range below 200°C, a small rate of change in dielectric constant with respect to temperature, and a small average linear expansion coefficient, making them suitable for use as high-temperature capacitors. Specific examples include electronic components used in high-temperature environments, such as power devices based on SiC or GaN, which are expected to be used in automotive devices, and electronic components used for noise reduction in the engine compartment of automobiles.

[0027] Furthermore, since the ceramic of the present invention has both excellent dielectric properties and a lower coefficient of linear expansion, it can be suitably used as a filler material for resins for electronic materials. By combining it with resin, the dielectric properties, electrical properties, heat resistance, etc. of the resin can be improved.

[0028] <Manufacturing method> The method for producing the ceramic of the present invention will now be described.

[0029] First, raw materials for each component constituting the ceramic of the present invention are prepared. The raw materials for each component are not particularly limited and can be appropriately selected from oxides or composite oxides of the above-mentioned components, or various compounds that become these oxides or composite oxides upon firing, such as carbonates, nitrates, hydroxides, fluorides, and organometallic compounds.

[0030] Next, the prepared raw materials are weighed and mixed to obtain a raw material mixture having a predetermined composition ratio. Examples of the mixing method include wet mixing using a ball mill and dry mixing using a dry mixer.

[0031] The obtained raw material mixture may be granulated by adding a binder resin, or may be made into a paste together with a binder resin and a solvent to make a slurry. Furthermore, the raw material mixture may be calcined before being made into a granulated product or a slurry.

[0032] The method for molding the granules or slurry is not particularly limited, and examples thereof include a sheet method, a printing method, dry molding, wet molding, and extrusion molding. For example, when dry molding is employed, the granules are filled into a mold and compressed under pressure (press) to form the molded product. The shape of the molded product is not particularly limited, and may be determined appropriately depending on the application.

[0033] The resulting molded body can be fired as needed by any method, such as atmospheric sintering, hot press sintering, hot isostatic sintering, spark plasma sintering, microwave sintering, etc., to obtain a ceramic dielectric (the ceramic of the present invention). Firing conditions can be determined appropriately depending on the firing method, composition, etc., but the firing temperature is preferably 1100°C to 1400°C, more preferably 1150°C to 1350°C, and even more preferably 1225°C to 1350°C, and the holding time (firing time) is preferably from several minutes to 24 hours.

[0034] The fired ceramic dielectric may be heat-treated in air, oxygen, or a reducing atmosphere as needed. Such heat treatment reduces defects and improves dielectric properties. The heat treatment temperature is preferably in the range of 900°C to 1200°C, and the treatment time is preferably in the range of 1 to 24 hours.

[0035] Furthermore, a ceramic capacitor that constitutes a dielectric layer of a multilayer electronic component can also be produced by a green sheet method, etc. That is, the ceramic powder of the present invention is made into a paste, a dielectric green sheet layer is formed on a carrier film by a doctor blade method, etc., a paste for an internal electrode layer is printed on this in a predetermined pattern, and then these are peeled off one by one, stacked, and molded into an integrated body under pressure, and fired at a temperature of about 800°C to 1200°C, thereby producing a ceramic capacitor.

[0036] The ceramics of the present invention can be formed into thin film dielectrics by using conventional thin film formation methods, such as vacuum deposition, high frequency sputtering, pulsed laser deposition (PLD), MOCVD (Metal Organic Chemical Vapor Deposition), MOD (Metal Organic Decomposition), sol-gel, and hydrothermal methods.

[0037] Therefore, the ceramic of the present invention may be used in electronic components such as single-plate capacitors, multilayer capacitors, thin-film electronic components, or piezoelectric elements. [Example]

[0038] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0039] <Ceramics manufacturing> (1-1) Mixing in a ball mill First, the raw materials NH4H2PO4, GeO2, Nb2O5, SiO2, and MnO2 were mixed in the specified ratio (see Table 1 below), and then packed into a polypot along with zirconia balls of 5 mm and 10 mm diameter, followed by the addition of ethanol.The mixture was then put into a ball mill and mixed for 18 hours. (1-2) Pre-baking The mixed batch was dried for 24 hours, then placed in a quartz crucible and pre-fired in an electric furnace in the atmosphere at 900°C to 1100°C for 2 to 4 hours. (1-3) Grinding with a ball mill The calcined powder was dried and crushed, then placed in the ball mill again and crushed for 24 to 36 hours. As in (1-1) above, 2 mm and 5 mm zirconia balls and ethanol were added to the powder before placing it in the ball mill. (1-4) Biaxial pressure molding After drying the calcined product, 1.5 g of the product was taken and filled into a metal mold with an inner diameter of 20 mm, and molded into pellets using a biaxial press under pressure conditions of 10 MPa and 1 minute. (1-5) Isostatic pressing The pellets were placed in a vinyl bag, evacuated, and then isostatically pressed in a CIP (cold isostatic press) device at 200 MPa for 2 minutes. (1-6) Final firing The pellets were sintered in air at 1200°C to 1300°C for 4 hours, and then slowly cooled to complete a disc-shaped ceramic.

[0040] 1. Ceramics evaluation The disk-shaped ceramics manufactured above were polished to a thickness of approximately 1.5 mm, and then XRD and dielectric properties (dielectric constant and dielectric loss) were measured. XRD was measured using an X-ray diffractometer (BRUKER, D8 DISCOVER) in the 2θ range of 10 to 60°. Dielectric properties were measured using an impedance analyzer (Solartron, SI1260) in the frequency range of 100 Hz to 100 kHz after gold electrodes were vapor-deposited on both sides of the sample. The temperature dependence of the dielectric properties was measured in the same frequency range from room temperature (25°C) to 200°C. The rate of change of dielectric constant with respect to temperature (temperature rate of change of dielectric constant: ε T ) was calculated by determining the change in each dielectric constant at each temperature when each dielectric constant at 25°C was used as the reference, using the following formula.

[0041] ε T (%) = [(Dielectric constant at target temperature - Dielectric constant at 25°C) / Dielectric constant at 25°C] x 100%

[0042] These average coefficients of linear expansion (CTE) were measured using a TD5000S manufactured by Mac Science, in accordance with the Japan Optical Glass Industry Association standard JOGIS-16 (2019), "Method for measuring the average coefficient of linear expansion of optical glass near room temperature." Specifically, the average coefficient of linear expansion of the disc-shaped ceramics manufactured above was calculated from the slope of the expansion curve, which shows the relationship between temperature and material elongation, in the temperature range of -30°C to 70°C.

[0043] Table 1 below shows the compositions (mol % relative to the total amount of material in the oxide-equivalent composition), sintering conditions, crystalline phase (main crystalline phase), dielectric constant and dielectric loss (tan δ) at a frequency of 1 kHz at 25°C, and average linear expansion coefficients at -30°C to 70°C of Examples 1 to 9 and Comparative Example 1. Although the examples vary depending on the composition, the main crystalline phase is PNbO 25 , GeNbO 25 , GeNb 18 O 47 , and their solid solutions (P,Ge)NbO 25 and / or (Ge,P)Nb 18 O 47 It was confirmed that at least one selected from the above was produced. Regarding the dielectric properties, it was confirmed that the Examples containing SiO2 and / or MnO2 had a higher dielectric constant and a lower dielectric loss. In addition, all Examples had an average linear expansion coefficient of 20 × 10 at -30 °C to 70 °C. -7 It was found to be less than / K.

[0044] 1 shows the frequency dependence of the dielectric constant at room temperature (25°C) for Example 1 and Comparative Example 1. From this figure, it was confirmed that the dielectric constant of Comparative Example 1 was around 600 (almost all less than 600) in the frequency range of 100 Hz to 100 kHz, while the dielectric constant of Example 1 was around 1400.

[0045] 2 shows the dielectric constant and dielectric loss of Example 1 at a frequency of 1 kHz in the temperature range from room temperature (25°C) to 200°C. From this figure, it was confirmed that the dielectric constant was 1000 or more and the dielectric loss was 1% or less in the range up to 200°C.

[0046] 3 shows the temperature coefficient of the dielectric constant at frequencies of 100 Hz, 1 kHz, 10 kHz, and 100 kHz in the temperature range from room temperature (25°C) to 200°C in Example 1. From this figure, it was found that the temperature coefficient of each dielectric constant in the temperature range below 200°C was 30% or less.

[0047] [Table 1]

Claims

1. Nb in mole percent relative to the total amount of material in the oxide-equivalent composition 2 O 5 Components: 82.0 to 96.0%, (P 2 O 5 +GeO 2 ) 3.0 to 15.0%, (SiO 2 + MnO 2 ) in an amount of more than 0.0% and not more than 5.0%, and has a dielectric constant of 600 or more and a dielectric loss of 5.0% or less at a frequency of 1 kHz at 25°C, and an average linear expansion coefficient of 50 x 10 -7 / K or less.

2. 2. The ceramic according to claim 1, wherein the temperature coefficient of the dielectric constant at frequencies of 100 Hz to 100 kHz in the range of 25° C. to 200° C. is 30% or less.

3. Nb 2 O 5 / (P 2 O 5 +GeO 2 3. The ceramic according to claim 1, wherein the value of σ is 7.0 to 20.

0.

4. As a crystalline phase, PNb 9 O 25 , GeNb 9 O 25 , GeNb 18 O 47 3. The ceramic according to claim 1, further comprising one or more elements selected from the group consisting of:

5. A dielectric comprising the ceramic according to claim 1 or 2.

6. A capacitor comprising the dielectric of claim 5.

7. A filler material comprising the ceramic according to claim 1 or 2.

8. A capacitor comprising the filler material of claim 7.

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