Potassium sodium niobate sintered body and sputtering target formed of said sintered body
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2025-04-15
- Publication Date
- 2026-05-27
Abstract
Description
Potassium sodium niobate sintered body and sputtering target made of said sintered body
[0001] The present disclosure relates to a potassium sodium niobate sintered body and a sputtering target made of the sintered body.
[0002] Lead-based PZT (lead zirconate titanate), which exhibits excellent piezoelectric properties, is used as a piezoelectric material in sensors and actuators. While PZT has good and stable piezoelectric properties, it contains lead, which places a heavy burden on the environment. In Europe, in particular, the Restriction of Hazardous Substances (RoHS) Directive and the End-of-Life Vehicles (ELV) Directive restrict its use as a highly environmentally hazardous substance. Therefore, the need for alternatives to lead-free piezoelectric materials has become a pressing issue.
[0003] Although various materials have been researched as replacements, it is not easy to find a material that matches the properties and stability of PZT, and PZT continues to be used as a material exempt from RoHS. In this context, potassium sodium niobate (KNN) is considered to exhibit piezoelectric properties relatively similar to those of PZT, and has been cited as a lead-free candidate for a PZT replacement. For example, Patent Document 1 discloses a piezoelectric material made of potassium sodium niobate.
[0004] Specifically, the composition formula (K ａ Na １－ａ ) ｘ NbO ３ (0.1<a<1, 1≦x≦1.2) is disclosed. It also describes adding an excess of potassium or sodium, or adding other components, as needed. The method for producing the piezoelectric layer describes applying a precursor solution having the composition of the above composition formula to a substrate, and then annealing and crystallizing the solution to produce a piezoelectric layer (sol-gel method). It also describes that the layer can be produced by other methods, such as MOD, laser ablation, and sputtering.
[0005] Patent Document 2 describes a sputtering target material that can produce a piezoelectric film (KNN film) of alkali niobium oxide. １－ｘ Na ｘ ) NbO ３ It is disclosed that a thin film is formed by RF magnetron sputtering using a sputtering target material made of a sintered body represented by (0<x<1). Specifically, it is disclosed that the sputtering target is a high-density potassium sodium niobate sputtering target.
[0006] JP 2014-033210 A JP 2019-161074 A International Publication No. 2019 / 167657
[0007] When a thin film is formed using a potassium sodium niobate sputtering target, the alkali component volatilizes, preventing the desired composition from being obtained, and also preventing the formation of a sintered body with a desired density. In view of these problems, an object of the present disclosure is to provide a dense potassium sodium niobate sintered body and a sputtering target made of the sintered body that can be used to form a thin film with a desired composition.
[0008] The gist of the present disclosure is as follows: [1] A ceramic ceramic material containing potassium (K), sodium (Na), niobium (Nb), and oxygen (O), having a composition satisfying the atomic ratio of 1.0<(K+Na) / Nb≦1.3, and having a dimensional density of 3.9 g / cm ３ The above potassium sodium niobate sintered body. [2] (K １－ｘ Na ｘ ) NbO ３ The X-ray diffraction peak intensity attributable to the (022) plane of the (0<x<1) phase is expressed as I ＴＧ The average value of the X-ray diffraction intensity in the range of 15.0°≦2θ≦16.0° is I ＢＧ When I ＴＧ / I ＢＧ [3] The potassium sodium niobate sintered body according to [1], having a volume resistivity of 1.0 × 10 or more. ４ Ω・cm or more, 1.0×10 １０The potassium sodium niobate sintered body according to claim 1 or 2, wherein the resistivity is Ω·cm or less. [4] A sputtering target comprising the potassium sodium niobate sintered body according to any one of [1] to [3].
[0009] According to the present disclosure, it is possible to provide a dense potassium sodium niobate sintered body and a sputtering target made of the sintered body, which can be used to form a thin film having a desired composition.
[0010] Below, the present disclosure will be described with reference to specific embodiments, but each configuration and combination thereof in each embodiment is merely an example, and addition, omission, substitution, and other modifications of configurations are possible as appropriate within the scope that does not deviate from the gist of the present disclosure.
[0011] [Potassium sodium niobate sintered body] An embodiment of the present disclosure is a potassium sodium niobate sintered body containing potassium (K), sodium (Na), niobium (Nb), and oxygen (O). The composition of the sintered body satisfies the atomic ratio of 1.0<(K+Na) / Nb≦1.3. In the formula, K, Na, and Nb respectively represent the atomic ratio (at%) of each component contained in the sintered body. Conventional potassium sodium niobate sintered bodies contain alkali metals (potassium, sodium) and niobium in an atomic ratio of 1:1. However, the potassium sodium niobate sintered body according to this embodiment is characterized by containing a higher amount of alkali metal relative to niobium (alkali-rich).
[0012] When a film is formed using a conventional potassium sodium niobate sintered body containing alkali metal and niobium in an atomic ratio of 1:1, the alkali metal component is reduced, and in the thin film, (K+Na) / Nb<0.9, and K １―ｘ Na ｘ NbO ３In some cases, the phase did not crystallize sufficiently, making it impossible to obtain the desired piezoelectric properties. In this embodiment, by forming a film using a potassium sodium niobate sintered body that satisfies 1<(K+Na) / Nb≦1.3, it is possible to form a thin film with 0.9≦(K+Na) / Nb≦1.1. The composition of the sintered body preferably satisfies the atomic ratio (K+Na) / Nb≦1.2, and more preferably (K+Na) / Nb≦1.1.
[0013] Moreover, the potassium sodium niobate sintered body according to this embodiment has a dimensional density of 3.9 g / cm ３ That's all. When a film is formed using this sintered body, the higher the dimensional density of the sintered body, the more particles can be suppressed during film formation. In the case of a conventional potassium sodium niobate sintered body containing an alkali metal and niobium in an atomic ratio of 1:1, the sintering temperature had to be set to 900°C or higher to improve density, but this posed the problem of severe wear of sintering equipment components. However, the potassium sodium niobate sintered body of the present disclosure has improved sinterability, and can achieve high density even at a sintering temperature of less than 900°C. More preferably, the dimensional density is 4.1 g / cm ３ That's all.
[0014] The potassium sodium niobate sintered body according to this embodiment is K １―ｘ Na ｘ NbO ３ The X-ray diffraction peak intensity attributable to the (022) plane of the (0<x<1) phase is expressed as I ＴＧ The average value of the X-ray diffraction intensity in the range of 15.0°≦2θ≦16.0° is I ＢＧ When I ＴＧ / I ＢＧ is preferably 50 or more. １―ｘ Na ｘ NbO ３ The (022) plane of the (0<x<1) phase usually exhibits a peak at a diffraction angle (2θ) of 45°≦2θ≦46°. ＴＧ / I ＢＧ If is 50 or more, K １―ｘ Na ｘ NbO ３On the other hand, if the crystallization is insufficient, the desired piezoelectric properties may not be obtained.
[0015] The potassium sodium niobate sintered body according to this embodiment has a volume resistivity of 1×10 ４ Ω・cm or more, 1×10 １０ The sputtering target made of the sintered body preferably has a volume resistivity of 1×10 ４ If the volume resistivity is Ω·cm or more, low-speed film formation by RF (Radio Frequency) sputtering becomes possible, and control of the film thickness becomes easy. More preferably, the volume resistivity is 1.0×10 ５ On the other hand, 1×10 １０ When the resistivity exceeds Ω cm, it becomes difficult to control the film properties by adjusting the conditions during sputtering. １０ The volume resistivity is preferably 1×10 Ω·cm or less. ９ It is Ω·cm or less.
[0016] The potassium sodium niobate sintered body according to this embodiment may contain one or more of the following dopants: Li, which is a Group 1 element; Mg, Ca, Sr, and Ba, which are Group 2 elements; Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, which are rare earth elements; Cu, Mn, Ti, V, Cr, Fe, Co, Ni, Cu, Zr, Mo, Ag, Hf, Ta, and W, which are amphoteric metal elements; and Si, Ge, Sn, Sb, and Bi, which are semimetal elements. The dopant can adjust the crystallinity, piezoelectric properties, and electrical properties of the piezoelectric film.
[0017] The sintered body of this embodiment can be used as a PVD (physical vapor deposition) material, and can be used, for example, as a sputtering target, a vacuum deposition material, an ion plating material, etc. When used as a sputtering target, it can be formed into a disk-shaped flat plate, a rectangular flat plate, or a cylindrical shape, and can be bonded to a backing plate with a bonding material. When used as a sputtering target, its thickness can be 20 mm or less, preferably 3.0 to 15 mm, and more preferably 6.0 to 12 mm. The area of the sputtered surface is 182 cm ２ It is preferable that this is equal to or greater than this.
[0018] [Method for manufacturing a potassium sodium niobate sintered body] A method for manufacturing a potassium sodium niobate sintered body, particularly a sputtering target, according to an embodiment of the present disclosure will be described. However, the manufacturing conditions and the like below are not limited to the disclosed range, and it is clear that some omissions and modifications may be made. Note that detailed descriptions of well-known manufacturing steps and processing operations will be omitted to avoid unnecessarily obscuring the disclosed manufacturing method.
[0019] (Raw material powder) As the raw material powder, Nb ２ O ５ powder, K ２ CO ３ Powder, Na ２ CO ３ Powder or KNbO ３ Powder, NaNbO ３ If the particle diameter of the raw material powder is large, for example, the particle diameter D ５０ If the median diameter is 1 mm or more, subsequent mixing and pulverization will be difficult, so it is desirable to pulverize each raw material powder before weighing.
[0020] (Mixing and grinding process) Nb ２ O ５ powder, K ２ CO ３ Powder, Na ２ CO ３Powders and other materials are weighed out to achieve the desired composition ratio (alkali-rich). After weighing, these are mixed. To obtain a dense, uniform sintered body, care must be taken to thoroughly finely grind and uniformly mix the materials using a mixer such as a ball mill or attritor.
[0021] (Synthesis Step) After mixing, the mixed powder is filled into an alumina or mullite sagger and heat-treated in an air atmosphere at 700°C or higher and 900°C or lower to produce a K powder having a desired composition. １―ｘ Na ｘ NbO ３ (0<x<1) Synthetic powder is obtained. If the heat treatment temperature is less than 700°C, K １―ｘ Na ｘ NbO ３ (0<x<1) may not be obtained. On the other hand, if the heat treatment temperature is higher than 900° C., there is a high possibility that the alkali component will volatilize.
[0022] (Pulverization step) After synthesis, the synthesized powder is dry-pulverized or wet-pulverized. In the case of wet-pulverization, the amount of media is determined according to the amount of raw material after weighing. The media diameter is 0.5 mm or 1.0 mm, and the media material is alumina (Al ２ O ３ ) and zirconia (ZrO ２ The dispersion medium is water or ethanol, and when water is used, it is preferable to recover the entire amount when taking out the mixed slurry. The pulverization method is wet ball mill pulverization or wet bead mill pulverization, and the pulverization time can be 1 hour or more. By using the above pulverization method, the particle diameter D ５０ It is preferable to mix and pulverize the powder until the median diameter is 2 μm or less. After wet mixing, the mixed powder is dried and then crushed and sieved. Since the alkaline component is easily volatilized, there is an upper limit to the sintering temperature in the subsequent process. Therefore, if the powder is not pulverized sufficiently, the density of the sintered body will not increase.
[0023] (Sintering Step) The mixed powder is preferably filled into a graphite mold and hot-pressed (H / P) sintered in an inert gas or vacuum atmosphere. When the raw material mixing ratio is 1.0<(K+Na) / Nb<1.1, the sintering temperature is preferably 710°C or higher and 880°C or lower. On the other hand, when the alkali metal composition ratio is 1.1≦(K+Na) / Nb≦1.3, the sintering temperature is preferably 710°C or higher and 800°C or lower. If the sintering temperature is too high, the alkali components will volatilize more and the graphite mold will be worn out more severely. On the other hand, if the sintering temperature is too low, a dense sintered body will not be obtained. In addition, the surface pressure should be 200 to 400 kgf / cm. ２ It is preferable that the surface pressure is 100 kgf / cm ２ If the density is less than 400 kgf / cm, the density of the sintered body will not be increased sufficiently. ２ If it exceeds this value, the possibility of cracking increases during sintering.
[0024] (Regarding Finishing) The sintered body obtained through the above-mentioned sintering step can be processed into a desired PVD material, as needed, using a processing machine such as a surface grinder, a cylindrical grinder, a machining machine, etc. In the case of a sputtering target, it can be formed into a flat disk, a rectangular shape, a cylindrical shape, etc.
[0025] The following description will be given based on examples and comparative examples. Note that these examples are merely examples and are not intended to limit the scope of the present invention. That is, the present invention is limited only by the scope of the claims, and includes various modifications other than the examples included in this disclosure.
[0026] The evaluation methods used in the examples and comparative examples are as follows: (Composition analysis) The composition of the sintered body was analyzed using the following device: Device: SPS3500DD manufactured by SII Corporation Method: ICP-OES (inductively coupled plasma optical emission spectroscopy)
[0027] (Dimensional density) A piece of a predetermined size (approximately 20 × 20 × 10 mm) was cut out from the sintered body, and the length, width, and thickness were measured with a vernier caliper, and the volume was calculated. The weight of the sintered body was also measured with an electronic balance, and the dimensional density (g / cm ３) = weight / volume was calculated. Lower limit of measurement of caliper: 0.01 mm Lower limit of measurement of electronic balance: 0.01 g
[0028] (Volume Resistivity) A measurement sample of the sintered body (center portion) was processed into a square shape, and the surface ground 2 mm from the surface was used to measure the volume resistivity three times and calculate the average value. Device: High-resistivity resistivity meter Hiresta-UX MCP-HT800 manufactured by Nitto Seiko Analytech Co., Ltd. Method: Constant voltage application / leakage current measurement method Method: Double ring method Measurement temperature: Room temperature (20 to 25°C) Applied voltage: 10 V
[0029] (Analysis of Crystalline Phase) Analysis of the crystalline phase was performed using the following equipment. Principle: X-ray diffraction method Equipment: Smart Lab manufactured by Rigaku Corporation Tube: Cu-Kα ray Tube voltage: 40 kV Current: 30 mA Measurement method: 2θ-θ reflection method Scan speed: 20° / min Sampling interval: 0.02° Measurement range (2θ): 10° to 60° Divergence slit: 1° Divergence vertical limiting slit: 10 mm Scattering slit: 8 mm Receiving slit: open state Goniometer: horizontal type for sample Sample measurement location: sputtered surface side
[0030] (Example 1) KNbO ３ Powder, NaNbO ３ powder, K ２ CO ３ Powder, Na ２ CO ３ The powders were weighed to a mixing ratio of (K+Na):Nb = 1.20:1 (atomic ratio), and then mixed in a blade rotary dry mixer. The blade rotation speed was set to 3000 rpm, and mixing was carried out for 3 minutes. Thereafter, this mixed powder was heat-treated at 800°C to obtain K. １－ｘ Na ｘ NbO ３ (0<x<1) Synthetic powder was prepared, and the obtained synthetic powder was subjected to wet bead mill pulverization. After wet bead mill pulverization, the powder was dried, crushed, and sieved through a 250 μm mesh. This crushed powder was used in an argon atmosphere, sintered at a temperature of 750°C, and subjected to a surface pressure of 250 kgf / cm. ２The resulting sintered body had a desired composition ratio of (K+Na) / Nb=1.21. The dimensional density was 4.26 g / cm. ３ and the volume resistivity is 1.40×10 ５ The results are shown in Table 1.
[0031]
[0032] (Example 2) KNbO ３ Powder, NaNbO ３ powder, K ２ CO ３ Powder, Na ２ CO ３ The powders were weighed so that the mixing ratio was (K+Na):Nb = 1.10:1 (atomic ratio), and then mixed in a blade rotary dry mixer. Then, the mixed powder was heat-treated at 800 °C to obtain K. １－ｘ NaxNbO ３ (0<x<1) Synthetic powder was prepared, and the obtained synthetic powder was wet bead milled. After wet bead milling, the powder was dried, crushed, and sieved in the same manner as in Example 1. This crushed powder was used in an argon atmosphere, sintered at a temperature of 750°C, and a surface pressure of 250 kgf / cm. ２ As shown in Table 1, the obtained sintered body had the desired composition ratio of (K+Na) / Nb=1.13. The dimensional density was 4.32 g / cm. ３ and the volume resistivity is 1.70×10 ５ Ω·cm, and the desired value was obtained.
[0033] (Example 3) KNbO ３ Powder, NaNbO ３ powder, K ２ CO ３ Powder, Na ２ CO ３ The powders were weighed so that the mixing ratio was (K+Na):Nb = 1.16:1 (atomic ratio), and then mixed in a blade rotary dry mixer. Then, the mixed powder was heat-treated at 800 °C to obtain K. １－ｘ NaxNbO ３(0<x<1) Synthetic powder was prepared, and the obtained synthetic powder was subjected to wet bead mill pulverization. After wet bead mill pulverization, the powder was dried, crushed, and sieved in the same manner as in Example 1. This crushed powder was used in an argon atmosphere, sintered at a temperature of 720°C and a surface pressure of 250 kgf / cm. ２ As shown in Table 1, the obtained sintered body had a desired composition ratio of (K+Na) / Nb=1.16. The dimensional density was 4.16 g / cm. ３ and the volume resistivity is 1.76×10 ６ Ω·cm, and the desired value was obtained.
[0034] (Example 4) KNbO ３ Powder, NaNbO ３ powder, K ２ CO ３ Powder, Na ２ CO ３ The powders were weighed so that the mixing ratio was (K+Na):Nb = 1.05:1 (atomic ratio), and then mixed in a blade rotary dry mixer. Then, the mixed powder was heat-treated at 800 °C to obtain K. １－ｘ NaxNbO ３ (0<x<1) Synthetic powder was prepared, and the obtained synthetic powder was subjected to wet bead mill pulverization. After wet bead mill pulverization, the powder was dried, crushed, and sieved in the same manner as in Example 1. This crushed powder was used in an argon atmosphere, sintered at a temperature of 875°C and a surface pressure of 250 kgf / cm. ２ As shown in Table 1, the obtained sintered body had a desired composition ratio of (K+Na) / Nb=1.05. The dimensional density was 3.90 g / cm. ３ and the volume resistivity is 6.21×10 ６ Ω·cm, and the desired value was obtained.
[0035] (Comparative Example 1) KNbO ３ Powder, NaNbO ３ powder, K ２ CO ３ Powder, Na ２ CO ３ The powders were weighed so that the mixing ratio was (K+Na):Nb = 1.20:1 (atomic ratio), and then mixed in a blade rotary dry mixer. Then, the mixed powder was heat-treated at 800°C to obtain K.１－ｘ Na ｘ NbO ３ (0<x<1) Synthetic powder was prepared, and the obtained synthetic powder was subjected to wet bead mill pulverization. Next, similar to Example 1, after wet bead mill pulverization, the powder was dried, crushed, and sieved. This crushed powder was used in an argon atmosphere, sintered at a temperature of 700°C and a surface pressure of 250 kgf / cm. ２ As shown in Table 1, the obtained sintered body had a desired composition ratio of (K+Na) / Nb=1.21, but the dimensional density was 3.85 g / cm ３ This is thought to be due to the low sintering temperature.
[0036] (Comparative Example 2) KNbO ３ Powder, NaNbO ３ powder, K ２ CO ３ Powder, Na ２ CO ３ The powders were weighed so that the mixing ratio was (K+Na):Nb = 1.20:1 (atomic ratio), and then mixed in a blade rotary dry mixer. Then, the mixed powder was heat-treated at 800°C to obtain K. １－ｘ Na ｘ NbO ３ (0<x<1) Synthetic powder was prepared, and the obtained synthetic powder was subjected to wet bead mill pulverization. Next, similar to Example 1, after wet bead mill pulverization, the powder was dried, crushed, and sieved. This crushed powder was used in an argon atmosphere, sintered at a temperature of 835°C and a surface pressure of 250 kgf / cm. ２ As shown in Table 1, the obtained sintered body did not have the desired composition ratio of (K+Na) / Nb=1.00. This is thought to be because the sintering temperature was high relative to the alkali metal composition ratio, causing the alkali components to volatilize.
[0037] (Comparative Example 3) KNbO ３ Powder, NaNbO ３ powder, K ２ CO ３ Powder, Na ２ CO ３The powders were weighed so that the mixing ratio was (K+Na):Nb = 1.20:1 (atomic ratio), and then mixed in a blade rotary dry mixer. Then, the mixed powder was heat-treated at 800°C to obtain K. １－ｘ Na ｘ NbO ３ (0<x<1) Synthetic powder was prepared, and the obtained synthetic powder was subjected to wet bead mill pulverization. Next, similar to Example 1, after wet bead mill pulverization, the powder was dried, crushed, and sieved. This crushed powder was used in an argon atmosphere, sintered at a temperature of 750°C and a surface pressure of 250 kgf / cm. ２ As shown in Table 1, the obtained sintered body had a desired composition ratio of (K+Na) / Nb=1.21, but the dimensional density was 3.89 g / cm ３ This is thought to be due to the large particle size of the pulverized powder after synthesis, although it is also due to the sintering temperature.
[0038] (Comparative Example 4) KNbO ３ Powder, NaNbO ３ The powders were weighed so that the mixing ratio was (K+Na):Nb = 1.00:1 (atomic ratio), and then mixed in a rotary blade dry mixer in the same manner as in Example 1. Thereafter, this mixed powder was heat-treated at 800°C to obtain K. １－ｘ Na ｘ NbO ３ (0<x<1) Synthetic powder was prepared, and the obtained synthetic powder was subjected to wet bead mill pulverization. Next, similar to Example 1, after wet bead mill pulverization, the powder was dried, crushed, and sieved. This crushed powder was used in an argon atmosphere, sintered at a temperature of 950°C and a surface pressure of 250 kgf / cm. ２ As shown in Table 1, the composition ratio of the obtained sintered body was (K+Na) / Nb=1.00. Because the sintering temperature was high, the graphite mold was severely worn away.
[0039] (Comparative Example 5) KNbO ３ Powder, NaNbO ３ powder, K ２ CO ３ Powder, Na ２ CO ３The powders were weighed so that the mixing ratio was (K+Na):Nb = 1.00:1 (atomic ratio), and then mixed in a blade rotary dry mixer. Then, the mixed powder was heat-treated at 800°C to obtain K. １－ｘ Na ｘ NbO ３ A (0<x<1) synthetic powder was prepared, and the obtained synthetic powder was wet bead milled. Next, similar to Example 1, after wet bead milling, the powder was dried, crushed, and sieved. Next, this crushed powder was filled into a mold and pressed to prepare a compact. Thereafter, the obtained compact was sintered under atmospheric pressure at a sintering temperature of 950°C in the air. As shown in Table 1, the obtained sintered body had a volume resistivity of 3.15 × 10 １０ It was high at Ω·cm.
[0040] (Comparative Example 6) KNbO ３ Powder, NaNbO ３ powder, K ２ CO ３ Powder, Na ２ CO ３ The powders were weighed so that the mixing ratio was (K+Na):Nb = 1.00:1 (atomic ratio), and then mixed in a blade rotary dry mixer. Then, the mixed powder was heat-treated at 800°C to obtain K. １－ｘ Na ｘ NbO ３ A (0<x<1) synthetic powder was prepared, and the obtained synthetic powder was subjected to wet bead mill pulverization. Next, similar to Example 1, after wet bead mill pulverization, the powder was dried, crushed, and sieved. Next, this crushed powder was filled into a mold and pressed to prepare a compact. Thereafter, the obtained compact was subjected to atmospheric sintering in an oxygen atmosphere at a sintering temperature of 950°C. As shown in Table 1, the obtained sintered body had a volume resistivity of 2.75 × 10 １１ It was high at Ω·cm.
[0041] According to the present disclosure, it is possible to provide a dense potassium sodium niobate sintered body and a sputtering target made of the sintered body, which are capable of producing a thin film having a desired composition and crystal phase. The potassium sodium niobate sputtering target according to the present embodiment can be used to form piezoelectric elements used in sensors, actuators, etc.
Claims
1. It contains potassium (K), sodium (Na), niobium (Nb), and oxygen (O), and its composition satisfies the atomic ratio of 1.0 < (K + Na) / Nb ≤ 1.3, with a dimensional density of 3.9 g / cm³. ３ The above is the result, and the volume resistivity is 1.0 × 10⁻⁶ ４ Ω・cm or more, 1.0×10 １０ A potassium sodium niobate sintered body with a density of Ω·cm or less.
2. (K １－ｘ Na ｘ ) NbO ３ The X-ray diffraction peak intensity belonging to the (022) plane of the (0 < x < 1) phase is I ＴＧ and the average value of the X-ray diffraction intensity in the range of 15.0° ≤ 2θ ≤ 16.0° is I ＢＧ When, I ＴＧ / I ＢＧ The potassium sodium niobate sintered body according to claim 1, wherein is 50 or more.
3. (delete)
4. A sputtering target comprising a potassium sodium niobate sintered body according to claim 1 or 2.