A method for producing a piezoelectric ceramic material having improved piezoelectric properties

Abstract

The application provides a preparation method of a piezoelectric ceramic material with improved piezoelectric performance, and the method comprises the following steps: providing a piezoelectric ceramic base material, wherein the chemical formula of the piezoelectric ceramic base material is BaTiO3.xTiO2.yZrO2; magnetron sputtering a first piezoelectric ceramic layer on the piezoelectric ceramic base material, wherein the chemical formula of the first piezoelectric ceramic layer is BaTiO3.aTiO2.bZrO2; magnetron sputtering a second piezoelectric ceramic layer on the first piezoelectric ceramic layer, wherein the chemical formula of the second piezoelectric ceramic layer is BaTiO3.cTiO2.dZrO2; and magnetron sputtering a third piezoelectric ceramic layer on the second piezoelectric ceramic layer, wherein the chemical formula of the third piezoelectric ceramic layer is BaTiO3.eTiO2.fZrO2; wherein x > a > c > e, and wherein y < b < d < f.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of piezoelectric ceramics, in particular to a preparation method of piezoelectric ceramic material with improved piezoelectric properties. BACKGROUND

[0002] Piezoelectric ceramics is a kind of electronic ceramic material with piezoelectric properties. The prior art CN116477938A discloses a barium titanate-based lead-free piezoelectric ceramic. The composition of the barium titanate-based lead-free piezoelectric ceramic proposed by the prior art is BaTiO3·xTiO2, and x is 0-0.005. The piezoelectric coefficient of the piezoelectric ceramic of the prior art is about 240-270, and the polarization rate (Kp) can reach 0.46. The present research group hopes to further improve the performance of the barium titanate-based lead-free piezoelectric ceramic of the prior art by means of magnetron sputtering. SUMMARY

[0003] To achieve the above-mentioned purpose, the present application provides a preparation method of piezoelectric ceramic material with improved piezoelectric properties, characterized in that the method comprises:

[0004] providing a piezoelectric ceramic base material, wherein the chemical formula of the piezoelectric ceramic base material is BaTiO3·xTiO2·yZrO2;

[0005] magnetron sputtering on the piezoelectric ceramic base material to form a first piezoelectric ceramic layer, wherein the chemical formula of the first piezoelectric ceramic layer is BaTiO3·aTiO2·bZrO2;

[0006] magnetron sputtering on the first piezoelectric ceramic layer to form a second piezoelectric ceramic layer, wherein the chemical formula of the second piezoelectric ceramic layer is BaTiO3·cTiO2·dZrO2;

[0007] magnetron sputtering on the second piezoelectric ceramic layer to form a third piezoelectric ceramic layer, wherein the chemical formula of the third piezoelectric ceramic layer is BaTiO3·eTiO2·fZrO2;

[0008] wherein x>a>c>e, and wherein y<b<d<f.

[0009] In a preferred embodiment, x=0.005-0.006, a=0.004-0.005, c=0.003-0.004, e=0.002-0.003, f=0.005-0.006, d=0.004-0.005, b=0.003-0.004, y=0.002-0.003.

[0010] In a preferred embodiment, the thickness of the piezoelectric ceramic base material is 100-120 microns, the thickness of the first piezoelectric ceramic layer is 20-25 microns, the thickness of the second piezoelectric ceramic layer is 10-15 microns, and the thickness of the third piezoelectric ceramic layer is 20-25 microns.

[0011] In a preferred embodiment, the specific process for forming the first piezoelectric ceramic layer on the piezoelectric ceramic base material by magnetron sputtering is as follows:

[0012] The sputtering target material is BaTiO3·aTiO2·bZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300-400 V, the sputtering power is 100-150 W, the sputtering temperature is 100-150 °C, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30-40 sccm.

[0013] In a preferred embodiment, the specific process for forming the second piezoelectric ceramic layer on the first piezoelectric ceramic layer by magnetron sputtering is as follows:

[0014] The sputtering target material is BaTiO3·cTiO2·dZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 100-200 V, the sputtering power is 300-350 W, the sputtering temperature is 100-150 °C, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30-40 sccm.

[0015] In a preferred embodiment, the specific process for forming the third piezoelectric ceramic layer on the second piezoelectric ceramic layer by magnetron sputtering is as follows:

[0016] The sputtering target material is BaTiO3·eTiO2·fZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300-400 V, the sputtering power is 100-150 W, the sputtering temperature is 100-150 °C, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30-40 sccm.

[0017] The present application provides a piezoelectric ceramic with improved piezoelectric properties, characterized in that the piezoelectric ceramic is formed by the following steps:

[0018] A piezoelectric ceramic base material is provided, wherein the chemical formula of the piezoelectric ceramic base material is BaTiO3·xTiO2·yZrO2;

[0019] A first piezoelectric ceramic layer is formed on the piezoelectric ceramic base material by magnetron sputtering, wherein the chemical formula of the first piezoelectric ceramic layer is BaTiO3·aTiO2·bZrO2;

[0020] A second piezoelectric ceramic layer is formed on the first piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the second piezoelectric ceramic layer is BaTiO3·cTiO2·dZrO2;

[0021] A third piezoelectric ceramic layer is formed on the second piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the third piezoelectric ceramic layer is BaTiO3·eTiO2·fZrO2.

[0022] wherein x>a>c>e, and wherein y<b<d<f.

[0023] In a preferred embodiment, x=0.005-0.006, a=0.004-0.005, c=0.003-0.004, e=0.002-0.003, f=0.005-0.006, d=0.004-0.005, b=0.003-0.004, and y=0.002-0.003.

[0024] In a preferred embodiment, the thickness of the piezoelectric ceramic substrate is 100-120 microns, the thickness of the first piezoelectric ceramic layer is 20-25 microns, the thickness of the second piezoelectric ceramic layer is 10-15 microns, and the thickness of the third piezoelectric ceramic layer is 20-25 microns.

[0025] In a preferred embodiment, the specific process for forming the first piezoelectric ceramic layer on the piezoelectric ceramic substrate by magnetron sputtering is as follows:

[0026] The sputtering target is BaTiO3·aTiO2·bZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300-400 V, the sputtering power is 100-150 W, the sputtering temperature is 100-150 °C, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30-40 sccm.

[0027] wherein the specific process for forming the second piezoelectric ceramic layer on the first piezoelectric ceramic layer by magnetron sputtering is as follows:

[0028] The sputtering target is BaTiO3·cTiO2·dZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 100-200 V, the sputtering power is 300-350 W, the sputtering temperature is 100-150 °C, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30-40 sccm.

[0029] wherein the specific process for forming the third piezoelectric ceramic layer on the second piezoelectric ceramic layer by magnetron sputtering is as follows:

[0030] The sputtering target is BaTiO3·eTiO2·fZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300-400 V, the sputtering power is 100-150 W, the sputtering temperature is 100-150 °C, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30-40 sccm.

[0031] Compared with the prior art, the barium titanate-based lead-free piezoelectric ceramic in the prior art is manufactured by a sintering method, but the sintered ceramic body has many internal defects, which leads to that the sintered piezoelectric ceramic cannot exert the full piezoelectric performance of the material. The method proposed in the present application adopts a magnetron sputtering method to prepare the piezoelectric ceramic, and the material prepared in the present application has fewer defects and has a certain degree of performance improvement compared with the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a method flow chart of an embodiment of the present application.

[0033] Figure 2 is a structural schematic diagram of an embodiment of the present application. DETAILED DESCRIPTION

[0034] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present application is not limited by the specific embodiments.

[0035] Figure 1 is a method flow chart of an embodiment of the present application. As shown in the figure, the method of the present application comprises the following steps:

[0036] Step 1: providing a piezoelectric ceramic base material, wherein the chemical formula of the piezoelectric ceramic base material is BaTiO3·xTiO2·yZrO2; in one example, the piezoelectric ceramic base material can be prepared by the preparation process disclosed in CN116477938A, and the difference from CN116477938A is that ZrO2 needs to be added when the piezoelectric ceramic base material is prepared; after the ceramic block is prepared by the method disclosed in CN116477938A, the ceramic sheet can be obtained by wire cutting, and then the thickness of the piezoelectric ceramic base material can be adjusted to the required thickness by sandpaper polishing or ion thinning. In another example, the piezoelectric ceramic base material can be directly ordered from a chemical shop, and the piezoelectric ceramic base material can also be obtained after the wire cutting, sandpaper polishing, ion thinning and other processes. It should be understood by those skilled in the art that a, b, c, d, e, f, x, y in the present application are molar ratios;

[0037] Step 2: magnetron sputtering to form a first piezoelectric ceramic layer on the piezoelectric ceramic base material, wherein the chemical formula of the first piezoelectric ceramic layer is BaTiO3·aTiO2·bZrO2;

[0038] Step 3: magnetron sputtering to form a second piezoelectric ceramic layer on the first piezoelectric ceramic layer, wherein the chemical formula of the second piezoelectric ceramic layer is BaTiO3·cTiO2·dZrO2;

[0039] Step 4: forming a third piezoelectric ceramic layer on the second piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the third piezoelectric ceramic layer is BaTiO3·eTiO2·fZrO2;

[0040] wherein x>a>c>e, and wherein y<b<d<f.

[0041] In a preferred embodiment, x=0.005-0.006, a=0.004-0.005, c=0.003-0.004, e=0.002-0.003, f=0.005-0.006, d=0.004-0.005, b=0.003-0.004, and y=0.002-0.003.

[0042] In a preferred embodiment, the thickness of the piezoelectric ceramic substrate is 100-120 microns, the thickness of the first piezoelectric ceramic layer is 20-25 microns, the thickness of the second piezoelectric ceramic layer is 10-15 microns, and the thickness of the third piezoelectric ceramic layer is 20-25 microns.

[0043] In a preferred embodiment, the specific process for forming the first piezoelectric ceramic layer on the piezoelectric ceramic substrate by magnetron sputtering is as follows:

[0044] The sputtering target is BaTiO3·aTiO2·bZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300-400 V, the sputtering power is 100-150 W, the sputtering temperature is 100-150 °C, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30-40 sccm. In one example, the BaTiO3·aTiO2·bZrO2 target can be directly ordered from a chemical store;

[0045] In a preferred embodiment, the specific process for forming the second piezoelectric ceramic layer on the first piezoelectric ceramic layer by magnetron sputtering is as follows:

[0046] The sputtering target is BaTiO3·cTiO2·dZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 100-200 V, the sputtering power is 300-350 W, the sputtering temperature is 100-150 °C, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30-40 sccm. In one example, the BaTiO3·cTiO2·dZrO2 target can be directly ordered from a chemical store;

[0047] In a preferred embodiment, the specific process for forming the third piezoelectric ceramic layer on the second piezoelectric ceramic layer by magnetron sputtering is as follows:

[0048] The sputtering target is BaTiO3·eTiO2·fZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300-400 V, the sputtering power is 100-150 W, the sputtering temperature is 100-150 °C, and the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30-40 sccm. In one example, the BaTiO3·eTiO2·fZrO2 target can be directly ordered from a chemical store.

[0049] Embodiments and comparative examples of the present application are described below.

[0050] Example 1

[0051] The piezoelectric ceramic material is prepared by the following method:

[0052] A piezoelectric ceramic substrate is provided, wherein the chemical formula of the piezoelectric ceramic substrate is BaTiO3·xTiO2·yZrO2; a first piezoelectric ceramic layer is formed on the piezoelectric ceramic substrate by magnetron sputtering, wherein the chemical formula of the first piezoelectric ceramic layer is BaTiO3·aTiO2·bZrO2; a second piezoelectric ceramic layer is formed on the first piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the second piezoelectric ceramic layer is BaTiO3·cTiO2·dZrO2; a third piezoelectric ceramic layer is formed on the second piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the third piezoelectric ceramic layer is BaTiO3·eTiO2·fZrO2; x = 0.005, a = 0.004, c = 0.003, e = 0.002, f = 0.005, d = 0.004, b = 0.003, and y = 0.002.

[0053] The thickness of the piezoelectric ceramic substrate is 100 microns, the thickness of the first piezoelectric ceramic layer is 20 microns, the thickness of the second piezoelectric ceramic layer is 10 microns, and the thickness of the third piezoelectric ceramic layer is 20 microns.

[0054] The specific process for forming the first piezoelectric ceramic layer on the piezoelectric ceramic substrate by magnetron sputtering is as follows: the sputtering target is BaTiO3·aTiO2·bZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300 V, the sputtering power is 100 W, the sputtering temperature is 100 °C, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30 sccm.

[0055] The specific process for forming the second piezoelectric ceramic layer on the first piezoelectric ceramic layer by magnetron sputtering is as follows: the sputtering target is BaTiO3·cTiO2·dZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 100 V, the sputtering power is 300 W, the sputtering temperature is 100 °C, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30 sccm.

[0056] The specific process for forming the third piezoelectric ceramic layer on the second piezoelectric ceramic layer by magnetron sputtering is as follows: the sputtering target is BaTiO3·eTiO2·fZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300 V, the sputtering power is 100 W, the sputtering temperature is 100°C, and the sputtering atmosphere is an argon atmosphere with a flow rate of 30 sccm. In order to perform testing, a silver electrode layer is formed on the third piezoelectric ceramic layer by magnetron sputtering, and the piezoelectric coefficient D33 and the polarization rate Kp of the piezoelectric ceramic are mainly tested, with the testing method referring to CN116477938A. The D33 of Example 1 is 310, and the Kp is 0.49. The piezoelectric ceramic performance of Example 1 of the present application has a certain improvement compared with the prior art CN116477938A. This improvement may mainly come from two aspects: first, the defects such as holes, cracks and charge defects in the piezoelectric ceramic layer prepared by magnetron sputtering are less than those in the ceramic material prepared by sintering, and the piezoelectric ceramic material of the present application contains a large number of piezoelectric ceramic layers, that is, in general, the composite piezoelectric ceramic material of the present application has fewer defects than the sintered ceramic material of CN116477938A, so the performance of the material of the present application is improved. Second, the piezoelectric performance is essentially related to the degree of electronic polarization, and the degree of electronic polarization is related to the crystal lattice structure and the crystal field. The multilayer composite material proposed in the present application has a richer crystal lattice structure (for example, the amount of titanium dioxide and zirconium dioxide is different, and the crystal lattice structure must have certain differences) and crystal field, which may lead to an increase in the degree of electronic polarization, thereby improving the performance of the present application.

[0057] Example 2

[0058] The piezoelectric ceramic material is prepared by the following method:

[0059] A piezoelectric ceramic substrate is provided, wherein the chemical formula of the piezoelectric ceramic substrate is BaTiO3·xTiO2·yZrO2; a first piezoelectric ceramic layer is formed on the piezoelectric ceramic substrate by magnetron sputtering, wherein the chemical formula of the first piezoelectric ceramic layer is BaTiO3·aTiO2·bZrO2; a second piezoelectric ceramic layer is formed on the first piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the second piezoelectric ceramic layer is BaTiO3·cTiO2·dZrO2; a third piezoelectric ceramic layer is formed on the second piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the third piezoelectric ceramic layer is BaTiO3·eTiO2·fZrO2; x = 0.006, a = 0.005, c = 0.004, e = 0.003, f = 0.006, d = 0.005, b = 0.004, and y = 0.003.

[0060] The thickness of the piezoelectric ceramic substrate is 120 microns, the thickness of the first piezoelectric ceramic layer is 25 microns, the thickness of the second piezoelectric ceramic layer is 15 microns, and the thickness of the third piezoelectric ceramic layer is 25 microns.

[0061] The specific process for forming the first piezoelectric ceramic layer on the piezoelectric ceramic substrate by magnetron sputtering is as follows: the sputtering target material is BaTiO3·aTiO2·bZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 400 V, the sputtering power is 150 W, the sputtering temperature is 150 °C, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30 sccm.

[0062] The specific process for forming the second piezoelectric ceramic layer on the first piezoelectric ceramic layer by magnetron sputtering is as follows: the sputtering target material is BaTiO3·cTiO2·dZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 200 V, the sputtering power is 350 W, the sputtering temperature is 150 °C, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30 sccm.

[0063] The specific process for forming the third piezoelectric ceramic layer on the second piezoelectric ceramic layer by magnetron sputtering is as follows: the sputtering target material is BaTiO3·eTiO2·fZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 400 V, the sputtering power is 150 W, the sputtering temperature is 150 °C, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30 sccm.

[0064] The D33 of Example 2 is 323, and the Kp is 0.53.

[0065] Example 3

[0066] The piezoelectric ceramic material is prepared by the following method:

[0067] A piezoelectric ceramic substrate is provided, wherein the chemical formula of the piezoelectric ceramic substrate is BaTiO3·xTiO2·yZrO2; a first piezoelectric ceramic layer is formed on the piezoelectric ceramic substrate by magnetron sputtering, wherein the chemical formula of the first piezoelectric ceramic layer is BaTiO3·aTiO2·bZrO2; a second piezoelectric ceramic layer is formed on the first piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the second piezoelectric ceramic layer is BaTiO3·cTiO2·dZrO2; a third piezoelectric ceramic layer is formed on the second piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the third piezoelectric ceramic layer is BaTiO3·eTiO2·fZrO2; x = 0.0055, a = 0.0045, c = 0.0035, e = 0.0025, f = 0.0055, d = 0.0045, b = 0.0035, and y = 0.0025.

[0068] The thickness of the piezoelectric ceramic substrate is 110 microns, the thickness of the first piezoelectric ceramic layer is 22 microns, the thickness of the second piezoelectric ceramic layer is 12 microns, and the thickness of the third piezoelectric ceramic layer is 22 microns.

[0069] The specific process for forming the first piezoelectric ceramic layer by magnetron sputtering on the piezoelectric ceramic substrate is as follows: the sputtering target material is BaTiO3·aTiO2·bZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 350 V, the sputtering power is 120 W, the sputtering temperature is 120 °C, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30 sccm.

[0070] The specific process for forming the second piezoelectric ceramic layer by magnetron sputtering on the first piezoelectric ceramic layer is as follows: the sputtering target material is BaTiO3·cTiO2·dZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 150 V, the sputtering power is 320 W, the sputtering temperature is 120 °C, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30 sccm.

[0071] The specific process for forming the third piezoelectric ceramic layer by magnetron sputtering on the second piezoelectric ceramic layer is as follows: the sputtering target material is BaTiO3·eTiO2·fZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 350 V, the sputtering power is 120 W, the sputtering temperature is 120 °C, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30 sccm.

[0072] The D33 of Example 3 is 315, and the Kp is 0.50.

[0073] Comparative Example 1

[0074] The piezoelectric ceramic material is prepared by the following method:

[0075] A piezoelectric ceramic substrate is provided, wherein the chemical formula of the piezoelectric ceramic substrate is BaTiO3·xTiO2·yZrO2; a first piezoelectric ceramic layer is formed by magnetron sputtering on the piezoelectric ceramic substrate, wherein the chemical formula of the first piezoelectric ceramic layer is BaTiO3·aTiO2·bZrO2; the thickness of the first piezoelectric ceramic layer is 50 microns, and the piezoelectric ceramic does not include a second piezoelectric ceramic layer and a third piezoelectric ceramic layer. The remaining parameters and step conditions are the same as in Example 1. The D33 of Comparative Example 1 is 243, and the Kp is 0.44. The reason for the performance decline of Comparative Example 1 is that Comparative Example 1 does not use a multi-layer composite structure, but only has one piezoelectric ceramic layer, so the crystal lattice structure and crystal field of the material are not rich, which leads to a decrease in piezoelectric performance. In addition, the present research group has found that plating a thick film on BaTiO3·xTiO2·yZrO2 can cause a large number of defects in the magnetron sputtering film layer, which also leads to a decrease in piezoelectric performance.

[0076] Comparative Example 2

[0077] x = 0.003, a = 0.004, c = 0.005, e = 0.006, f = 0.003, d = 0.004, b = 0.005, y = 0.006. The rest of the parameters and step conditions are the same as in Example 1. D33 of Comparative Example 2 is 270, and Kp is 0.45. The explanation for Comparative Example 2 can refer to Comparative Example 1.

[0078] Comparative Example 3

[0079] The specific process for forming the first piezoelectric ceramic layer on the piezoelectric ceramic substrate by magnetron sputtering is as follows: the sputtering target material is BaTiO3-aTiO2-bZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 100 V, the sputtering power is 300 W, the sputtering temperature is 200 °C, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30 seem. The rest of the parameters and step conditions are the same as in Example 1. D33 of Comparative Example 3 is 221, and Kp is 0.40. The performance of Comparative Example 3 is mainly due to the poor sputtering process of the film layer and the poor quality of the film layer.

[0080] Comparative Example 4

[0081] The specific process for forming the second piezoelectric ceramic layer on the first piezoelectric ceramic layer by magnetron sputtering is as follows: the sputtering target material is BaTiO3-cTiO2-dZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 350 V, the sputtering power is 100 W, the sputtering temperature is 120 °C, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30 seem. The rest of the parameters and step conditions are the same as in Example 1. D33 of Comparative Example 4 is 258, and Kp is 0.45.

[0082] Comparative Example 5

[0083] The specific process for forming the third piezoelectric ceramic layer on the second piezoelectric ceramic layer by magnetron sputtering is as follows: the sputtering target material is BaTiO3-eTiO2-fZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 100 V, the sputtering power is 300 W, the sputtering temperature is 150 °C, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30 seem. The rest of the parameters and step conditions are the same as in Example 1. D33 of Comparative Example 5 is 287, and Kp is 0.48.

[0084] The foregoing description of specific exemplary embodiments of the application has been presented for the purposes of illustration and explanation. It is not intended to be exhaustive or to limit the application to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the principles of the application and its practical application and to thereby enable others skilled in the art to best utilize the application and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the application be defined by the claims and their equivalents.

Claims

1. A method for producing a piezoelectric ceramic material having improved piezoelectric properties, characterized by, The method comprises: providing a piezoelectric ceramic substrate, wherein the chemical formula of the piezoelectric ceramic substrate is BaTiO3·xTiO2·yZrO2; forming a first piezoelectric ceramic layer on the piezoelectric ceramic substrate by magnetron sputtering, wherein the chemical formula of the first piezoelectric ceramic layer is BaTiO3·aTiO2·bZrO2; forming a second piezoelectric ceramic layer on the first piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the second piezoelectric ceramic layer is BaTiO3·cTiO2·dZrO2; forming a third piezoelectric ceramic layer on the second piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the third piezoelectric ceramic layer is BaTiO3·eTiO2·fZrO2; wherein x>a>c>e, and wherein y<b<d<f; wherein x=0.005-0.006, a=0.004-0.005, c=0.003-0.004, e=0.002-0.003, f=0.005-0.006, d=0.004-0.005, b=0.003-0.004, y=0.002-0.

003.

2. The method of claim 1, wherein, The thickness of the piezoelectric ceramic substrate is 100-120 microns, the thickness of the first piezoelectric ceramic layer is 20-25 microns, the thickness of the second piezoelectric ceramic layer is 10-15 microns, and the thickness of the third piezoelectric ceramic layer is 20-25 microns.

3. The method of claim 2, wherein, The specific process for forming the first piezoelectric ceramic layer on the piezoelectric ceramic substrate by magnetron sputtering is: The sputtering target material is BaTiO3·aTiO2·bZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300-400V, the sputtering power is 100-150W, the sputtering temperature is 100-150℃, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30-40sccm.

4. The method of claim 3, wherein, The specific process for forming the second piezoelectric ceramic layer on the first piezoelectric ceramic layer by magnetron sputtering is: The sputtering target material is BaTiO3·cTiO2·dZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 100-200V, the sputtering power is 300-350W, the sputtering temperature is 100-150℃, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30-40sccm.

5. The method of claim 4, wherein, The specific process for forming the third piezoelectric ceramic layer on the second piezoelectric ceramic layer by magnetron sputtering is: The sputtering target material is BaTiO3·eTiO2·fZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300-400V, the sputtering power is 100-150W, the sputtering temperature is 100-150℃, and the sputtering atmosphere is an argon atmosphere with an argon flow rate of 30-40sccm.

6. A piezoelectric ceramic having improved piezoelectric properties, characterized by, The piezoelectric ceramic is formed by the following steps: providing a piezoelectric ceramic substrate, wherein the chemical formula of the piezoelectric ceramic substrate is BaTiO3·xTiO2·yZrO2; forming a first piezoelectric ceramic layer on the piezoelectric ceramic substrate by magnetron sputtering, wherein the chemical formula of the first piezoelectric ceramic layer is BaTiO3·aTiO2·bZrO2; A second piezoelectric ceramic layer is formed on the first piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the second piezoelectric ceramic layer is BaTiO3·cTiO2·dZrO2; A third piezoelectric ceramic layer is formed on the second piezoelectric ceramic layer by magnetron sputtering, wherein the chemical formula of the third piezoelectric ceramic layer is BaTiO3·eTiO2·fZrO2; wherein x>a>c>e, and wherein y<b<d<f; wherein x=0.005-0.006, a=0.004-0.005, c=0.003-0.004, e=0.002-0.003, f=0.005-0.006, d=0.004-0.005, b=0.003-0.004, y=0.002-0.

003.

7. The piezoelectric ceramic according to claim 6, wherein, The thickness of the piezoelectric ceramic substrate is 100-120 microns, the thickness of the first piezoelectric ceramic layer is 20-25 microns, the thickness of the second piezoelectric ceramic layer is 10-15 microns, and the thickness of the third piezoelectric ceramic layer is 20-25 microns.

8. The piezoelectric ceramic according to claim 7, wherein, The specific process for forming the first piezoelectric ceramic layer on the piezoelectric ceramic substrate by magnetron sputtering is as follows: The sputtering target material is BaTiO3·aTiO2·bZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300-400V, the sputtering power is 100-150W, the sputtering temperature is 100-150℃, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30-40sccm; The specific process for forming the second piezoelectric ceramic layer on the first piezoelectric ceramic layer by magnetron sputtering is as follows: The sputtering target material is BaTiO3·cTiO2·dZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 100-200V, the sputtering power is 300-350W, the sputtering temperature is 100-150℃, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30-40sccm; The specific process for forming the third piezoelectric ceramic layer on the second piezoelectric ceramic layer by magnetron sputtering is as follows: The sputtering target material is BaTiO3·eTiO2·fZrO2, the sputtering power source is a radio frequency power source, the sputtering voltage is 300-400V, the sputtering power is 100-150W, the sputtering temperature is 100-150℃, the sputtering atmosphere is an argon atmosphere, and the argon flow rate is 30-40sccm.

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