A niobium-manganese-doped lead niobate-yttrium ytterbium lead zirconate titanate piezoelectric ceramic and its preparation method

Abstract

The present invention discloses a manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic and a preparation method thereof. The chemical formula of the manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic is: xwt.% MnNbO4 - yPb(Yb 0.5 Nb 0.5 )O3 - zPbZrO3 - (1 - y - z)PbTiO3, where 1.4 ≤ x ≤ 1.8, 0.1 ≤ y ≤ 0.14, and 0.37 ≤ z ≤ 0.42. The piezoelectric ceramic of the present invention is prepared by doping with manganese niobate and using a solid-phase sintering method, and a manganese niobate-doped lead ytterbium niobate-lead zirconate titanate (MnN-PYN-PZT) piezoelectric ceramic with a high mechanical quality factor and excellent piezoelectric coefficient is obtained. This piezoelectric ceramic can better meet the basic performance requirements of high-power devices such as high-power ultrasonic welding machines and ultrasonic flaw detectors.

Description

Technical Field

[0001] The present invention belongs to the technical field of piezoelectric ceramic preparation, and particularly relates to a lead niobate ytterbium manganese-doped lead zirconate titanate piezoelectric ceramic and a preparation method thereof. Background Art

[0002] Piezoelectric materials are an important type of functional materials that can directly achieve the mutual conversion between mechanical energy and electrical energy. They are widely used in fields such as sensors, actuators, and ultrasonic transducers, and also play an important role in multiple fields such as automotive electronics, information communication, and aerospace. Among piezoelectric materials, PZT-based piezoelectric ceramics have been widely studied and applied due to their advantages such as simple preparation, short production cycle, low production cost, and easy repetition, and have almost monopolized the piezoelectric ceramic market within half a century.

[0003] High-power devices include high-power ultrasonic welding machines, ultrasonic flaw detectors, Bolt axial force meters, etc., which require a high mechanical quality factor (above 1200) and a high Curie temperature (above 250 °C). Currently, the piezoelectric ceramics used in high-power devices are still mainly classic commercial PZT-4 and PZT-8. However, although PZT-4 and PZT-8 piezoelectric ceramics have advantages such as good electromechanical properties, high stability, and low manufacturing cost, with the development of industry, the working environment of high-power devices has become increasingly complex, and traditional PZT-4 and PZT-8 gradually struggle to meet the performance requirements of high-power devices for materials. Therefore, it is urgent to develop piezoelectric ceramics with excellent comprehensive performance.

[0004] The core component of high-power devices, the piezoelectric transducer, frequently undergoes electromechanical conversion during operation, inevitably generating waste heat, causing a local temperature rise in the device, and in severe cases, may cause device failure. Engineers generally use two methods to reduce the impact of the waste heat generated during device operation on the device, namely, designing a more scientific and reasonable heat dissipation structure and selecting a more suitable high-power piezoelectric material. There is an empirical formula:

[0005] H DVE = M V0 2 w0 / 2Q m

[0006] H DVE That is, the heat generation rate, which describes the heat generated per second by the piezoelectric oscillator during the operation of the ultrasonic transducer. In the formula, M represents the mass of the piezoelectric oscillator, V0 represents the vibration rate of the piezoelectric oscillator, Q m is the mechanical quality factor of the piezoelectric oscillator, and w0 is the resonant frequency of the piezoelectric oscillator. It can be seen from the formula that the larger the mechanical quality factor, the smaller the heat loss during the operation of the ultrasonic transducer. Developing piezoelectric ceramics with good temperature stability and high mechanical quality factor is of great significance for the design and development of high-power devices. Summary of the Invention

[0007] In view of the deficiencies of the prior art, the present invention provides a manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic and a preparation method thereof. Through manganese niobate doping and process optimization, the present invention obtains a high-power piezoelectric ceramic with both a high Curie temperature, good temperature stability, and good electromechanical properties.

[0008] The technical solution of the present invention is as follows:

[0009] A manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic, the chemical formula of the manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic being: xwt.%MnNbO4-yPb(Yb 0.5 Nb 0.5 )O3-zPbZrO3-(1-y-z)PbTiO3, where 1.4 ≤ x ≤ 1.8, 0.1 ≤ y ≤ 0.14, 0.37 ≤ z ≤ 0.42.

[0010] A preparation method of the manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic, comprising the following steps:

[0011] (1) After proportioning YbNbO4 precursor, MnNbO4 precursor, TiO2, ZrO2, and PbO according to the stoichiometry of xwt.%MnNbO4-yPb(Yb 0.5 Nb 0.5 )O3-zPbZrO3-(1-y-z)PbTiO3, 1.4 ≤ x ≤ 1.8, 0.1 ≤ y ≤ 0.14, 0.37 ≤ z ≤ 0.42, ball milling evenly to obtain a mixture, drying, and then grinding to obtain a ground material;

[0012] (2) Pre-sintering the ground material to obtain a pre-sintered powder with a pure perovskite phase, and then performing secondary ball milling and drying to obtain a dry powder;

[0013] (3) Granulating, sieving, and pressing the dry powder into a green sheet, and sintering the green sheet after debinding treatment to obtain a manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic, i.e., MnN-PYN-PZT piezoelectric ceramic.

[0014] Further, the piezoelectric coefficient of the MnN-PYN-PZT piezoelectric ceramic is 180-230 pC / N, the mechanical quality factor is 1057-1973, the Curie temperature is 350-400 °C, the planar electromechanical coupling coefficient k p is 0.5-0.6, the relative dielectric constant at room temperature is 800-1500, the remanent polarization intensity is 15-22 μC / cm 2 , and the coercive field is 17-19 kV / cm.

[0015] Further, the resonant frequency f of the MnN-PYN-PZT piezoelectric ceramic ranges from 20°C to 80°C r has a temperature coefficient of -223 to -116 ppm / °C, and the temperature coefficient of the electromechanical coupling coefficient k p is 47 to 299 ppm / °C.

[0016] Further, in step (1), the preparation method of the YbNbO4 precursor is as follows: According to the chemical formula of YbNbO4, raw materials Yb2O3 and Nb2O5 are weighed in a molar ratio of 1:1. After mixing Yb2O3 and Nb2O5, they are ball-milled and then dried to obtain dry raw material powder. After grinding, they are calcined to obtain the YbNbO4 precursor. The preparation of the precursor can prevent the appearance of the pyrochlore phase during the sintering process, and the pyrochlore phase will deteriorate the performance of the material.

[0017] Further, the molar ratio of Yb2O3 to Nb2O5 is 1:1; the ball-milling is wet ball-milling, that is, anhydrous ethanol is used as the ball-milling medium, and the volume ratio of anhydrous ethanol to the raw materials is approximately 4:1; the speed of the ball-milling is 200 - 300 r / min, and the time is 8 - 12 h; the drying temperature is 80 - 100°C, and the time is 3 - 4 h. The grinding is manual grinding using a mortar to grind the dried powder, and the time is about 20 - 40 min; the calcination temperature is 1200°C - 1250°C, and the time is 2 - 4 h.

[0018] Further, in step (1), the preparation method of the MnNbO4 precursor is: After mixing MnO2 and Nb2O5, they are ball-milled and dried to obtain dry powder. After grinding, they are calcined to obtain the MnNbO4 precursor.

[0019] Further, in step (1), a horizontal ball mill is used for the ball-milling.

[0020] Further, the molar ratio of MnO2 to Nb2O5 is 1:1; the ball-milling is wet ball-milling, that is, anhydrous ethanol is used as the ball-milling medium, and the volume ratio of anhydrous ethanol to the raw materials is approximately 4:1; the speed of the ball-milling is 200 - 300 r / min, and the time is 8 - 12 h; the drying temperature is 80 - 100°C, and the time is 3 - 4 h. The grinding is manual grinding using a mortar to grind the dried powder, and the time is about 20 - 40 min; the calcination temperature is 1100°C - 1200°C, and the time is 2 - 6 h.

[0021] Further, in step (1), the rotation speed of the ball-milling is 200 - 300 r / min, and the time is 8 - 12 h; the drying temperature is 80 - 100°C, and the time is 3 - 4 h.

[0022] Further, in step (2), the temperature of the pre-sintering is 850 - 900 °C, and the time is 2 - 2.5 h; the secondary ball milling is wet ball milling, that is, anhydrous ethanol is used as the ball milling medium, the volume ratio of anhydrous ethanol to the raw materials is about 4:1, and the ball milling time is 8 - 12 h; the drying temperature is 80 - 100 °C, and the time is 2 - 4 h.

[0023] Further, in step (3), the granulation is to granulate the dried powder with an aqueous solution of polyvinyl alcohol, and the mass-to-volume ratio of the dried powder to the aqueous solution of polyvinyl alcohol is 10 - 15:1; the mass concentration of the aqueous solution of polyvinyl alcohol is 3 - 5%; the aperture of the sieve used for sieving is 200 mesh; the debinding treatment is to use a muffle furnace to heat the ceramic blank at a heating rate of 2 - 3 °C / min to 600 - 650 °C, keep it warm for 2 - 3 h, and then cool it to room temperature at a cooling rate of 5 °C / min; the sintering process is to use a muffle furnace to heat the debound ceramic blank from room temperature at a heating rate of 4 - 6 °C / min to 1000 - 1050 °C, and then heat it at a heating rate of 2 - 4 °C / min to 1100 - 1200 °C, then keep it warm for 2 - 4 h, and after the heat preservation ends, cool it to room temperature at a cooling rate of 4 - 6 °C / min to complete the ceramic sintering process.

[0024] One kind of the manganese niobate doped lead niobium ytterbium zirconate titanate piezoelectric ceramic is used for high-power devices, meeting the basic requirements of high-power devices for piezoelectric ceramics. The high-power device preferably has a product frequency of 10 - 40 kHz, an input voltage of 220V alternating voltage, and a product power of 1000 - 4000W.

[0025] The beneficial technical effects of the present invention are as follows:

[0026] The manganese niobate doped lead niobium ytterbium zirconate titanate (MnN-PYN-PZT) piezoelectric ceramic prepared by the present invention has both a high Curie temperature, a high mechanical quality factor, good piezoelectric activity and good temperature stability; among them, the piezoelectric coefficient is about 180 - 230 pC / N, the mechanical quality factor is 1057 - 1973, the Curie temperature is 350 - 400 °C, the planar electromechanical coupling coefficient kp is 0.5 - 0.6, the relative dielectric constant at room temperature is 800 - 1500, and the remanent polarization intensity is 15 - 22 μC / cm 2 , and the coercive field is 17 - 19 kV / cm; from 20 °C to 80 °C, the temperature coefficient of the resonance frequency f r is -223 - -116 ppm / °C, and the temperature coefficient of the electromechanical coupling coefficient k p is 47 - 299 ppm / °C.

[0027] In the present invention, through the doping of manganese niobate, not only the pinning effect of oxygen vacancies generated by manganese doping on domain walls in piezoelectric ceramics is utilized, but also the restrictive effect of defect dipoles introduced by manganese doping on domain wall movement in piezoelectric ceramics. Compared with traditional doping of manganese carbonate or manganese oxide, the phase structure of the material changes, that is, the proportions of the rhombohedral phase and the tetragonal phase change, and the proportion of the rhombohedral phase increases. At the same time, the combined action of niobium and manganese affects the sintering process of piezoelectric ceramics, greatly reducing the grain size of lead niobium ytterbium-zirconate titanate piezoelectric ceramics, and greatly improving the mechanical quality factor of the material by utilizing the grain boundary effect.

[0028] The MnN-PYN-PZT piezoelectric ceramics prepared by the present invention can meet the basic performance requirements of high-power devices such as high-power ultrasonic welding machines and ultrasonic flaw detectors; the Curie temperature of the piezoelectric ceramics is higher than that of general commercial high-power piezoelectric ceramics, and it has a larger operating temperature range.

[0029] The preparation method of the manganese niobate-doped lead niobium ytterbium-zirconate titanate (MnN-PYN-PZT) piezoelectric ceramics of the present invention is prepared by a solid-phase sintering method, and this method is simple to operate. The preparation of the manganese niobate and niobium ytterbium acid precursors effectively avoids the generation of pyrochlore phases during the sintering process, and at the same time obtains a high mechanical quality factor and excellent piezoelectric coefficients. Brief Description of the Drawings

[0030] Figure 1 It is the X-ray diffraction pattern of the MnN-PYN-PZT piezoelectric ceramics prepared in Example 2 of the present invention.

[0031] Figure 2 It is the SEM pattern and particle size distribution of the MnN-PYN-PZT piezoelectric ceramics prepared in Example 2 of the present invention.

[0032] Figure 3 It is the relationship diagram of the dielectric constant, dielectric loss and temperature of the MnN-PYN-PZT piezoelectric ceramics prepared in Example 2 of the present invention.

[0033] Figure 4 It is the ferroelectric hysteresis loop diagram of the MnN-PYN-PZT piezoelectric ceramics prepared in Example 2 of the present invention.

[0034] Figure 5 It is the impedance spectrum of the MnN-PYN-PZT piezoelectric ceramics prepared in Example 2 of the present invention.

[0035] Figure 6 It is the relationship diagram of the resonance frequency, electromechanical coupling coefficient and temperature of the MnN-PYN-PZT piezoelectric ceramics prepared in Example 2 of the present invention.

[0036] In the figure: (a) shows the relationship between the resonant frequency of the piezoelectric ceramic and temperature when heated from room temperature to 350°C; (b) shows the relationship between the electromechanical coupling coefficient of the piezoelectric ceramic and temperature when heated from room temperature to 350°C. Detailed implementation mode

[0037] The present invention will be specifically described below with reference to the accompanying drawings and embodiments.

[0038] A lead zirconate titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate, the chemical formula of the lead zirconate titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate is: x wt.% MnNbO4 - yPb(Yb 0.5 Nb 0.5 )O3 - zPbZrO3 - (1 - y - z)PbTiO3, where 1.4 ≤ x ≤ 1.8, 0.1 ≤ y ≤ 0.14, 0.37 ≤ z ≤ 0.42.

[0039] In an embodiment of the present invention, the chemical formula of the lead zirconate titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate is: x wt.% MnNbO4 - yPb(Yb 0.5 Nb 0.5 )O3 - zPbZrO3 - (1 - y - z)PbTiO3, where x is 1.4, y is 0.13, and z is 0.48.

[0040] In an embodiment of the present invention, the chemical formula of the lead zirconate titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate is: x wt.% MnNbO4 - yPb(Yb 0.5 Nb 0.5 )O3 - zPbZrO3 - (1 - y - z)PbTiO3, where x is 1.6, y is 0.13, and z is 0.48.

[0041] In an embodiment of the present invention, the chemical formula of the lead zirconate titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate is: x wt.% MnNbO4 - yPb(Yb 0.5 Nb 0.5 )O3 - zPbZrO3 - (1 - y - z)PbTiO3, where x is 1.8, y is 0.13, and z is 0.48.

[0042] In an embodiment of the present invention, the chemical formula of the lead zirconate titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate is: x wt.% MnNbO4 - yPb(Yb 0.5 Nb 0.5 )O3 - zPbZrO3 - (1 - y - z)PbTiO3, where x is 1.4, y is 0.1, and z is 0.42.

[0043] In one embodiment of the present invention, the chemical formula of the manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic is: x wt.% MnNbO4 - yPb(Yb 0.5 Nb 0.5 )O3 - zPbZrO3 - (1 - y - z)PbTiO 34 , where x is 1.4, y is 0.14, and z is 0.37.

[0044] A method for preparing the manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic includes the following steps:

[0045] (1) After proportioning YbNbO4 precursor, MnNbO4 precursor, TiO2, ZrO2, and PbO according to the stoichiometry of xwt.% MnNbO4 - yPb(Yb 0.5 Nb 0.5 )O3 - zPbZrO3 - (1 - y - z)PbTiO3, where 1.4 ≤ x ≤ 1.8, 0.1 ≤ y ≤ 0.14, 0.37 ≤ z ≤ 0.42, ball milling evenly to obtain a mixture, drying, and then grinding to obtain a ground material;

[0046] (2) Pre-sinter the ground material to obtain a pre-sintered powder with a pure perovskite phase, and then perform secondary ball milling and drying to obtain a dried powder;

[0047] (3) Granulate, screen, and press the dried powder into a green sheet, and after debinding the green sheet, sinter it to obtain the manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic, i.e., MnN-PYN-PZT piezoelectric ceramic.

[0048] In one embodiment of the present invention, the piezoelectric coefficient of the MnN-PYN-PZT piezoelectric ceramic is 180 - 230 pC / N, the mechanical quality factor is 1057 - 1973, the Curie temperature is 350 - 400 °C, the planar electromechanical coupling coefficient k p is 0.5 - 0.6, the relative dielectric constant at room temperature is 800 - 1500, the remanent polarization intensity is 15 - 22 μC / cm 2 , and the coercive field is 17 - 19 kV / cm.

[0049] In one embodiment of the present invention, the temperature coefficient of the resonant frequency f r of the MnN-PYN-PZT piezoelectric ceramic is -223 - -116 ppm / °C from 20 °C to 80 °C, and the temperature coefficient of the electromechanical coupling coefficient k p is 47 - 299 ppm / °C.

[0050] In one embodiment of the present invention, in step (1), the method for preparing the YbNbO4 precursor is as follows: according to the chemical formula of YbNbO4, weigh the raw materials Yb2O3 and Nb2O5. After mixing Yb2O3 and Nb2O5, perform ball milling, and then perform drying treatment to obtain dry raw material powder. After grinding, perform calcination to obtain the YbNbO4 precursor. The preparation of the precursor can prevent the appearance of the pyrochlore phase during the sintering process, and the pyrochlore phase will deteriorate the performance of the material.

[0051] In one embodiment of the present invention, the molar ratio of Yb2O3 to Nb2O5 is 1:1; the ball milling is wet ball milling, that is, using anhydrous ethanol as the ball milling medium, and the volume ratio of anhydrous ethanol to the raw materials is approximately 4:1; the speed of the ball milling is 200 r / min, 220 r / min, 250 r / min or 300 r / min, and the time is 8 h, 10 h, 11 h or 12 h; the drying temperature is 80 °C, 90 °C or 100 °C, and the time is 3 h, 3.5 h or 4 h. The grinding is manual grinding, using a mortar to grind the dried powder, and the time is about 20 min, 30 min, 35 min or 40 min; the calcination temperature is 1200 °C, 1210 °C, 1220 °C or 1250 °C, and the time is 2 h, 3 h or 4 h.

[0052] In one embodiment of the present invention, in step (1), after mixing MnO2 and Nb2O5, perform ball milling, and then perform subsequent drying treatment to obtain dry powder. After grinding, perform calcination to obtain the MnNbO4 precursor.

[0053] In one embodiment of the present invention, in step (1), a horizontal ball mill is used for the ball milling.

[0054] In one embodiment of the present invention, the molar ratio of MnO2 to Nb2O5 is 1:1; the ball milling is wet ball milling, that is, using anhydrous ethanol as the ball milling medium, and the volume ratio of anhydrous ethanol to the raw materials is approximately 4:1; the speed of the ball milling is 200 r / min, 220 r / min, 250 r / min or 300 r / min, and the time is 8 h, 10 h, 11 h or 12 h; the drying temperature is 80 °C, 90 °C or 100 °C, and the time is 3 h, 3.5 h or 4 h. The grinding is manual grinding using a mortar to grind the dried powder, and the time is about 20 min, 30 min, 35 min or 40 min; the calcination temperature is 1100 °C, 1110 °C, 1120 °C or 1200 °C, and the time is 2 h, 4 h, 5 h or 6 h.

[0055] In one embodiment of the present invention, in step (1), the rotation speed of the ball milling is 200 r / min, 220 r / min, 250 r / min or 300 r / min, and the time is 8 h, 10 h, 11 h or 12 h; the drying temperature is 80 °C, 90 °C or 100 °C, and the time is 3 h, 3.5 h or 4 h.

[0056] In one embodiment of the present invention, in step (2), the pre-sintering temperature is 850 °C, 870 °C or 900 °C, and the time is 2 h, 2.2 h or 2.5 h; the secondary ball milling is wet ball milling, that is, anhydrous ethanol is used as the ball milling medium, and the volume ratio of anhydrous ethanol to the raw material is approximately 4:1, and the ball milling time is 8 h, 10 h, 11 h or 12 h; the drying temperature is 80 °C, 90 °C or 100 °C, and the time is 2 h, 3 h or 4 h.

[0057] In one embodiment of the present invention, in step (3), the granulation is to granulate the dried powder with an aqueous solution of polyvinyl alcohol, and the mass-volume ratio of the dried powder to the aqueous solution of polyvinyl alcohol is 10:1, 11:1 or 15:1; the mass concentration of the aqueous solution of polyvinyl alcohol is 3%, 4% or 5%; the aperture of the sieve used for sieving is 200 mesh; the debinding treatment is to use a muffle furnace to heat the ceramic green body at a heating rate of 2 °C / min, 2.5 °C / min or 3 °C / min to 600 °C, 620 °C or 650 °C, and keep it warm for 2 h, 2.5 h or 3 h, and then cool it to room temperature at a cooling rate of 5 °C / min; the sintering process is to use a muffle furnace to heat the debound ceramic green body from room temperature at a heating rate of 4 °C / min, 5 °C / min or 6 °C / min to 1000 °C, 1020 °C or 1050 °C, and then heat it at a heating rate of 2 °C / min, 2.5 °C / min or 4 °C / min to 1100 °C, 1150 °C or 1200 °C, and then keep it warm for 2 h, 3 h or 4 h, and after the heat preservation is completed, cool it to room temperature at a cooling rate of 4 °C / min, 5 °C / min or 6 °C / min to complete the ceramic sintering process.

[0058] The present invention will be further described below through examples.

[0059] Example 1

[0060] A niobium manganese-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic with both high Curie temperature and mechanical quality factor, and its chemical composition is 1.4 wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3;

[0061] Its preparation method is as follows:

[0062] (1) 14.7795 g of Yb2O3 (99.99%) and 9.9779 g of Nb2O5 (99.9%) were weighed and placed in a ball mill. The mixture was ball milled at 200 r / min on a horizontal ball mill for 12 h (the ball milling was wet ball milling, i.e., anhydrous ethanol was used as the ball milling medium, and the volume ratio of anhydrous ethanol to the raw materials was approximately 4:1). The mixture was then dried at 80°C for 3 h. The dried powder was transferred to a crucible and manually ground for 20 min. Finally, the mixture was sintered at 1200°C for 2 h to obtain the precursor YbNbO4.

[0063] Weigh 6.6536g of MnO2 (98%) and 9.9779g of Nb2O5 (99.9%) and put them into a ball mill. Mill them at 200r / min on a horizontal ball mill (the ball milling is a wet ball milling method, i.e., anhydrous ethanol is used as the ball milling medium, and the volume ratio of anhydrous ethanol to the raw material is approximately 4:1) for 12 hours, then dry them at 80℃ for 3 hours, transfer the dried powder to a crucible and grind it manually for 20 minutes, and finally sinter at 1200℃ for 2 hours to obtain the precursor MnNbO4.

[0064] According to 1.4wt.%MnNbO4-0.13Pb(Yb 0.5 Nb 0.5 )O3-0.39PbZrO3-0.48PbTiO3 stoichiometric ratios were obtained. 2.1457g of YbNbO4, 0.4763g of MnNbO4, 23.2349g of PbO (99.9%), 4.8061g of ZrO2 (99.99%), and 3.8341g of TiO2 (99.99%) were weighed and placed in a ball mill. 30ml of anhydrous ethanol was added and the mixture was ball milled at 200 rpm for 12 hours in a horizontal ball mill. After thorough ball milling, the mixture was dried in an oven at 80°C for 3 hours. The dried mixture was then ground to obtain a grind.

[0065] (2) The ground material was placed in a corundum crucible and compacted, and then the crucible was transferred to a muffle furnace and heated to 850°C at a heating rate of 5°C / min. After being kept at this temperature for two hours, it was cooled to room temperature to obtain 1.4wt.% MnNbO4-0.13Pb(Yb 0.5 Nb 0.5 )O3-0.39PbZrO3-0.48PbTiO3 ceramic pre-calcined powder. The pre-calcined powder was then transferred to a ball mill and milled on a horizontal ball mill at 200 r / min for 12 hours (wet ball milling was used, i.e., anhydrous ethanol was used as the milling medium, and the volume ratio of anhydrous ethanol to the raw material was approximately 4:1). It was then dried at 80°C for 2 hours to obtain dry 1.4wt.% MnNbO4-0.13Pb(Yb 0.5 Nb0.5 ) O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic powder.

[0066] (3) Weigh 10 grams of 1.4wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 ) O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic powder and put it into a mortar. Add 1 mL of 5wt.% PVA aqueous solution for granulation, and the PVA aqueous solution is added dropwise in several times. Then, pass through a 200 - mesh sample sieve to obtain granulated powder. Weigh 0.55 g of the granulated powder and put it into a mold with a diameter of 10 mm for tabletting. Under a pressure of 10 Mpa, keep the pressure for 15 s to obtain a green sheet. Put the green sheet into a muffle furnace and heat it at a heating rate of 2 °C / min to 600 °C, keep it warm for 2 hours to remove the binder, and then cool it to room temperature at a cooling rate of 5 °C / min. The degreased green sheet is put into a muffle furnace in a buried - firing manner and heated at a heating rate of 5 °C / min to 1000 °C, then heated at a heating rate of 3 °C / min to 1200 °C, keep it warm for 2 hours, and then cool it to room temperature at a cooling rate of 4 °C / min to obtain a 1.4wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 ) O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic sheet.

[0067] Use sandpaper to polish the 1.4wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 ) O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic sheet to a thickness of 0.7 mm, and the surface is smooth and uniform. Then, evenly brush silver paste on the upper and lower surfaces of the ceramic sheet, and then put it into a muffle furnace and heat it at a heating rate of 5 °C / min to 560 °C, keep it warm for 20 minutes to obtain a ceramic sheet with silver electrodes. Use sandpaper to remove the excess silver layer on the edge, and then polarize it in a 120 °C silicone oil bath under an electric field of 40 kV / cm for 30 minutes to obtain a piezoelectric ceramic with macroscopic piezoelectric properties.

[0068] Example 2

[0069] A lead - zirconate - titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate with both high Curie temperature and mechanical quality factor, and its chemical composition is 1.6wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 ) O3 - 0.39PbZrO3 - 0.48PbTiO3;

[0070] Its preparation method is as follows:

[0071] (1) Weigh 14.7795 g of Yb2O3 (99.99%) and 9.9779 g of Nb2O5 (99.9%) and put them into a ball milling jar. Ball mill and mix them for 12 hours at a speed of 200 r / min on a horizontal ball mill (the ball milling is wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry them at 80 °C for 3 h. Transfer the dried powder to a crucible and manually grind it for 20 min. Finally, sinter it at 1200 °C for 2 hours to obtain the precursor YbNbO4.

[0072] Weigh 6.6536 g of MnO2 (98%) and 9.9779 g of Nb2O5 (99.9%) and put them into a ball milling jar. Ball mill and mix them for 12 hours at a speed of 200 r / min on a horizontal ball mill (the ball milling is wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry them at 80 °C for 3 h. Transfer the dried powder to a crucible and manually grind it for 20 min. Finally, sinter it at 1200 °C for 2 hours to obtain the precursor MnNbO4.

[0073] According to the stoichiometric ratio of 1.6 wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3, weigh 2.1457 g of YbNbO4, 0.5443 g of MnNbO4, 23.2349 g of PbO (99.9%), 4.8061 g of ZrO2 (99.99%) and 3.8341 g of TiO2 (99.99%) respectively and put them into a ball milling jar. Add 30 ml of absolute ethanol and ball mill them for 12 hours at a speed of 200 r / min on a horizontal ball mill. After fully ball milling and mixing evenly, put the mixed raw materials into an oven and dry them at 80 °C for 3 h. Grind the dried mixed powder to obtain the ground material.

[0074] (2) Grind the ground material obtained after grinding the dried mixed powder, put it into a corundum crucible and compact it. Then transfer the crucible to a muffle furnace and heat it up to 850 °C at a heating rate of 5 °C / min. Keep it at this temperature for two hours and then cool it to room temperature to obtain the 1.6 wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic pre-sintered powder. Then transfer the pre-sintered powder to a ball milling jar and ball mill it for 12 hours at a speed of 200 r / min on a horizontal ball mill (using wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry it at 80 °C for 2 h to obtain the dried 1.6 wt.% MnNbO4 - 0.13Pb(Yb0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic powder.

[0075] (3) Take 10 grams of 1.6wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic powder and put it into a mortar. Add 1 mL of 5wt.% PVA aqueous solution for granulation, and the PVA aqueous solution is added dropwise in several times. Then pass through a 200 - mesh sample sieve to obtain granulated powder. Weigh 0.55 g of the granulated powder and put it into a mold with a diameter of 10 mm for pressing. Under a pressure of 10 Mpa, keep the pressure for 15 s to obtain a green sheet. Put the green sheet into a muffle furnace and heat it at a heating rate of 2 °C / min to 600 °C, keep it warm for 2 hours to remove the binder, and then cool it at a cooling rate of 5 °C / min to room temperature. The green sheet after debinding is put into the muffle furnace in a buried - firing manner and heated at a heating rate of 5 °C / min to 1000 °C, then heated at a heating rate of 3 °C / min to 1200 °C, keep it warm for 2 hours, and then cool it at a cooling rate of 4 °C / min to room temperature to obtain 1.6wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic sheet.

[0076] Use sandpaper to polish the 1.6wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic sheet to a thickness of 0.7 mm and with a smooth and uniform surface. Then evenly brush silver paste on the upper and lower surfaces of the ceramic sheet, and then put it into a muffle furnace and heat it at a heating rate of 5 °C / min to 560 °C, keep it warm for 20 minutes to obtain a ceramic sheet with silver electrodes. Use sandpaper to remove the excess silver layer on the edge, and then polarize it in a 120 °C silicone oil bath under an electric field of 40 kV / cm for 30 minutes to obtain a piezoelectric ceramic with macroscopic piezoelectric properties.

[0077] Example 3

[0078] A lead - ytterbium niobate - lead zirconate titanate piezoelectric ceramic doped with manganese niobate with both high Curie temperature and mechanical quality factor, and its chemical composition is 1.8wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3;

[0079] Its preparation method is as follows:

[0080] (1) Weigh 14.7795 g of Yb2O3 (99.99%) and 9.9779 g of Nb2O5 (99.9%) and put them into a ball milling jar. Ball mill and mix them for 12 hours at a speed of 200 r / min on a horizontal ball mill (the ball milling is wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry them at 80 °C for 3 h. Transfer the dried powder to a crucible and manually grind it for 20 min. Finally, sinter it at 1200 °C for 2 hours to obtain the precursor YbNbO4.

[0081] Weigh 6.6536 g of MnO2 (98%) and 9.9779 g of Nb2O5 (99.9%) and put them into a ball milling jar. Ball mill and mix them for 12 hours at a speed of 200 r / min on a horizontal ball mill (the ball milling is wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry them at 80 °C for 3 h. Transfer the dried powder to a crucible and manually grind it for 20 min. Finally, sinter it at 1200 °C for 2 hours to obtain the precursor MnNbO4.

[0082] According to the stoichiometric ratio of 1.8 wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3, weigh 2.1457 g of YbNbO4, 0.6124 g of MnNbO4, 23.2349 g of PbO (99.9%), 4.8061 g of ZrO2 (99.99%) and 3.8341 g of TiO2 (99.99%) respectively and put them into a ball milling jar. Add 30 ml of absolute ethanol and ball mill at a speed of 200 r / min on a horizontal ball mill for 12 hours. After fully ball milling and mixing evenly, put the mixed raw materials into an oven and dry them at 80 °C for 3 h. Grind the dried mixed powder to obtain the ground material.

[0083] (2) Grind the ground material obtained after grinding the dried mixed powder, put it into a corundum crucible and compact it. Then transfer the crucible to a muffle furnace and heat it up to 850 °C at a heating rate of 5 °C / min. Keep it warm for two hours and then cool it to room temperature to obtain 1.8 wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic pre-sintered powder. Then transfer the pre-sintered powder to a ball milling jar and ball mill it for 12 hours at a speed of 200 r / min on a horizontal ball mill (using wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry it at 80 °C for 2 h to obtain the dried 1.8 wt.% MnNbO4 - 0.13Pb(Yb0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic powder.

[0084] (3) Weigh 10 g of 1.8 wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic powder and put it into a mortar. Add 1 mL of 5 wt.% PVA aqueous solution for granulation, and the PVA aqueous solution is added dropwise in multiple times. Then, pass through a 200 - mesh sieve to obtain granulated powder.

[0085] Weigh 0.55 g of the granulated powder and put it into a mold with a diameter of 10 mm for pressing. Under a pressure of 10 Mpa, keep the pressure for 15 s to obtain a green compact. Put the green compact into a muffle furnace and heat it at a heating rate of 2 °C / min to 600 °C, keep it warm for 2 hours to remove the binder, and then cool it at a cooling rate of 5 °C / min to room temperature. The binder - removed green compact is put into the muffle furnace in a buried - firing manner and heated at a heating rate of 5 °C / min to 1000 °C, then heated at a heating rate of 3 °C / min to 1200 °C, keep it warm for 2 hours, and then cool it at a cooling rate of 4 °C / min to room temperature to obtain 1.8 wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic sheet.

[0086] Use sandpaper to polish the 1.8 wt.% MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3 ceramic sheet to a thickness of 0.7 mm with a smooth and uniform surface. Then, evenly brush silver paste on the upper and lower surfaces of the ceramic sheet, and then put it into a muffle furnace and heat it at a heating rate of 5 °C / min to 560 °C, keep it warm for 20 minutes to obtain a ceramic sheet with silver electrodes. Use sandpaper to remove the excess silver layer on the edge, and then polarize it in a 120 °C silicone oil bath under an electric field of 40 kV / cm for 30 minutes to obtain a piezoelectric ceramic with macroscopic piezoelectric properties.

[0087] Example 4

[0088] A lead - ytterbium niobate - lead zirconate titanate piezoelectric ceramic doped with manganese niobate with both high Curie temperature and mechanical quality factor, whose chemical composition is 1.4 wt.% MnNbO4 - 0.10Pb(Yb 0.5 Nb 0.5 )O3 - 0.37PbZrO3 - 0.53PbTiO3), and its preparation method is as follows:

[0089] (1) Weigh 14.7795 g of Yb2O3 (99.99%) and 9.9779 g of Nb2O5 (99.9%) and put them into a ball milling jar. Ball mill and mix them at a speed of 250 r / min on a horizontal ball mill for 8 hours (the ball milling is wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry them in an oven at 90 °C for 3.5 h. Transfer the dried powder to a crucible and grind it manually for 30 min. Finally, sinter it at 1220 °C for 3 hours to obtain the precursor YbNbO4.

[0090] Weigh 6.6536 g of MnO2 (98%) and 9.9779 g of Nb2O5 (99.9%) and put them into a ball milling jar. Ball mill and mix them at a speed of 250 r / min on a horizontal ball mill (the ball milling is wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1) for 8 hours. Then dry them in an oven at 90 °C for 3.5 h. Transfer the dried powder to a crucible and grind it manually for 30 min. Finally, sinter it at 1100 °C for 3.5 hours to obtain the precursor MnNbO4.

[0091] According to the stoichiometric ratio of 1.4 wt.% MnNbO4 - 0.10Pb(Yb 0.5 Nb 0.5 )O3 - 0.37PbZrO3 - 0.53PbTiO3, weigh 1.6505 g of YbNbO4, 0.4594 g of MnNbO4, 23.2349 g of PbO (99.9%), 3.6971 g of ZrO2 (99.99%) and 4.2335 g of TiO2 (99.99%) respectively and put them into a ball milling jar. Then add 30 ml of absolute ethanol and ball mill them at a speed of 250 r / min on a horizontal ball mill for 8 hours. After fully ball milling and mixing evenly, put the mixed raw materials into an oven and dry them at 90 °C for 3.5 h. Grind the dried mixed powder to obtain the ground material.

[0092] (2) Put the ground material after grinding into a corundum crucible and compact it. Then transfer the crucible to a muffle furnace and heat it up to 870 °C at a heating rate of 5 °C / min. After holding for 2.2 hours, cool it to room temperature to obtain the 1.4 wt.% MnNbO4 - 0.10Pb(Yb 0.5 Nb 0.5 )O3 - 0.37PbZrO3 - 0.53PbTiO3 ceramic pre-sintered powder. Then transfer the pre-sintered powder to a ball milling jar and ball mill it at a speed of 200 r / min on a horizontal ball mill for 8 hours (using wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry it in an oven at 90 °C for 3 h to obtain the dried 1.4 wt.% MnNbO4 - 0.10Pb(Yb 0.5Nb 0.5 )O3 - 0.37PbZrO3 - 0.53PbTiO3 ceramic powder.

[0093] (3) Weigh 11 grams of 1.4wt.% MnNbO4 - 0.10Pb(Yb 0.5 Nb 0.5 )O3 - 0.37PbZrO3 - 0.53PbTiO3 ceramic powder and put it into a mortar. Add 1 mL of 3wt.% PVA aqueous solution for granulation, and the PVA aqueous solution is added dropwise in several times. Then, pass through a 200 - mesh sample sieve to obtain granulated powder. Weigh 0.55 g of the granulated powder and put it into a mold with a diameter of 10 mm for pressing. Under a pressure of 10 Mpa, keep the pressure for 15 s to obtain a green sheet. Put the green sheet into a muffle furnace and heat it at a heating rate of 2.5°C / min to 620°C, keep it warm for 2.5 hours to remove the binder, and then cool it to room temperature at a cooling rate of 5°C / min. The binder - removed green sheet is placed in the muffle furnace in a buried - firing manner and heated at a heating rate of 4°C / min to 1020°C, and then heated at a heating rate of 2°C / min to 1100°C. After keeping it warm for 3 hours, cool it to room temperature at a cooling rate of 5°C / min to obtain 1.4wt.% MnNbO4 - 0.10Pb(Yb 0.5 Nb 0.5 )O3 - 0.37PbZrO3 - 0.53PbTiO3 ceramic sheet.

[0094] Use sandpaper to grind the 1.4wt.% MnNbO4 - 0.10Pb(Yb 0.5 Nb 0.5 )O3 - 0.37PbZrO3 - 0.53PbTiO3 ceramic sheet to a thickness of 0.7 mm, and the surface is smooth and uniform. Then, evenly brush silver paste on the upper and lower surfaces of the ceramic sheet, and then put it into a muffle furnace and heat it at a heating rate of 5°C / min to 560°C, keep it warm for 20 minutes to obtain a ceramic sheet with silver electrodes. Use sandpaper to remove the excess silver layer on the edge, and then polarize it in a 120°C silicone oil bath under an electric field of 40 kV / cm for 30 minutes to obtain a piezoelectric ceramic with macroscopic piezoelectric properties.

[0095] Example 5

[0096] A lead - ytterbium niobate - lead zirconate - titanate piezoelectric ceramic doped with manganese niobate with both high Curie temperature and mechanical quality factor, whose chemical composition is 1.8wt.% MnNbO4 - 0.14Pb(Yb 0.5 Nb 0.5 )O3 - 0.42PbZrO3 - 0.44PbTiO3;

[0097] Its preparation method is as follows:

[0098] (1) Weigh 14.7795 g of Yb2O3 (99.99%) and 9.9779 g of Nb2O5 (99.9%) and put them into a ball milling pot. Ball mill and mix them for 10 hours at a speed of 300 r / min on a horizontal ball mill (the ball milling is wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry them at 100 °C for 4 h. Transfer the dried powder to a crucible and manually grind it for 40 min. Finally, sinter it at 1250 °C for 4 hours to obtain the precursor YbNbO4.

[0099] Weigh 6.6536 g of MnO2 (98%) and 9.9779 g of Nb2O5 (99.9%) and put them into a ball milling pot. Ball mill and mix them for 10 hours at a speed of 300 r / min on a horizontal ball mill (the ball milling is wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry them at 100 °C for 4 h. Transfer the dried powder to a crucible and manually grind it for 40 min. Finally, sinter it at 1150 °C for 6 hours to obtain the precursor MnNbO4.

[0100] According to the stoichiometric ratio of 1.8 wt.% MnNbO4 - 0.14Pb(Yb 0.5 Nb 0.5 )O3 - 0.42PbZrO3 - 0.44PbTiO3, weigh 2.3107 g of YbNbO4, 0.6267 g of MnNbO4, 23.2349 g of PbO (99.9%), 5.1758 g of ZrO2 (99.99%) and 3.5146 g of TiO2 (99.99%) respectively and put them into a ball milling pot. Add 30 ml of absolute ethanol and ball mill them for 10 hours at a speed of 300 r / min on a horizontal ball mill. After fully ball milling and mixing evenly, put the mixed raw materials into an oven and dry them at 100 °C for 4 h. Grind the dried mixed powder to obtain the ground material.

[0101] (2) Put the ground material after grinding into a corundum crucible and compact it. Then transfer the crucible to a muffle furnace and heat it up to 900 °C at a heating rate of 5 °C / min. After keeping it warm for 2.5 hours, cool it to room temperature to obtain the 1.8 wt.% MnNbO4 - 0.14Pb(Yb 0.5 Nb 0.5 )O3 - 0.42PbZrO3 - 0.44PbTiO3 ceramic pre-sintered powder. Then transfer the pre-sintered powder to a ball milling pot and ball mill it for 10 hours at a speed of 200 r / min on a horizontal ball mill (using wet ball milling, that is, using absolute ethanol as the ball milling medium, and the volume ratio of absolute ethanol to raw materials is approximately 4:1). Then dry it at 100 °C for 4 h to obtain the dried 1.8 wt.% MnNbO4 - 0.14Pb(Yb 0.5Nb 0.5 )O3 - 0.42PbZrO3 - 0.44PbTiO3 ceramic powder.

[0102] (3) Weigh 15 grams of 1.8wt.% MnNbO4 - 0.14Pb(Yb 0.5 Nb 0.5 )O3 - 0.42PbZrO3 - 0.44PbTiO3 ceramic powder and put it into a mortar. Add 1 mL of 4wt.% PVA aqueous solution for granulation, and the PVA aqueous solution is added dropwise in several times. Then, pass through a 200 - mesh sample sieve to obtain the granulated powder. Weigh 0.55 g of the granulated powder and put it into a mold with a diameter of 10 mm for tabletting. Under a pressure of 10 Mpa, keep the pressure for 15 s to obtain a green sheet. Put the green sheet into a muffle furnace and heat it at a heating rate of 3°C / min to 650°C, keep it warm for 3 hours to remove the binder, and then cool it at a cooling rate of 5°C / min to room temperature. The green sheet after debinding is put into the muffle furnace in a buried - firing manner and heated at a heating rate of 6°C / min to 1050°C, then heated at a heating rate of 4°C / min to 1150°C. After keeping it warm for 4 hours, cool it at a cooling rate of 6°C / min to room temperature to obtain 1.8wt.% MnNbO4 - 0.14Pb(Yb 0.5 Nb 0.5 )O3 - 0.42PbZrO3 - 0.44PbTiO3 ceramic sheet.

[0103] Use sandpaper to grind the 1.8wt.% MnNbO4 - 0.14Pb(Yb 0.5 Nb 0.5 )O3 - 0.42PbZrO3 - 0.44PbTiO3 ceramic sheet to a thickness of 0.7 mm, and the surface is smooth and uniform. Then, evenly brush silver paste on the upper and lower surfaces of the ceramic sheet, and then put it into a muffle furnace and heat it at a heating rate of 5°C / min to 560°C, keep it warm for 20 minutes to obtain a ceramic sheet with silver electrodes. Use sandpaper to remove the excess silver layer on the edge, and then polarize it in a 120°C silicone oil bath under an electric field of 40 kV / cm for 30 minutes to obtain a piezoelectric ceramic with macroscopic piezoelectric properties.

[0104] Comparative Example 1

[0105] A lead ytterbium niobate - lead zirconate titanate piezoelectric ceramic, whose chemical composition is 0MnNbO4 - 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3; its preparation method is as follows:

[0106] (1) Weigh 14.7795 g of Yb2O3 (99.99%) and 9.9779 g of Nb2O5 (99.9%) and put them into a ball milling jar. Ball mill and mix them at a speed of 200 r / min on a horizontal ball mill for 12 hours. Then dry them at 80 °C. Transfer the dried powder to a crucible and finally sinter it at 1200 °C for 2 hours to obtain the precursor YbNbO4.

[0107] (2) According to the stoichiometric ratio of 0.13Pb(Yb 0.5 Nb 0.5 )O3 - 0.39PbZrO3 - 0.48PbTiO3, weigh 2.1457 g of YbNbO4, 23.2349 g of PbO (99.9%), 4.8061 g of ZrO2 (99.99%) and 3.8341 g of TiO2 (99.99%) respectively and put them into a ball milling jar. Then add 30 ml of absolute ethanol and ball mill at a speed of 200 r / min on a horizontal ball mill for 12 hours. After fully ball milling and mixing evenly, put the mixed raw materials into an oven and dry them at 80 °C.

[0108] (3) Grind the dried mixed powder, put it into a corundum crucible and compact it. Then transfer the crucible to a muffle furnace and heat it up to 850 °C at a heating rate of 5 °C / min. Keep it at this temperature for two hours and then cool it to room temperature to obtain the 0.13PYN - 0.39PZ - 0.48PT ceramic pre - sintered powder. Then transfer the pre - sintered powder to a ball milling jar and ball mill at a speed of 200 r / min on a horizontal ball mill for 12 hours, and then dry it at 80 °C.

[0109] (4) Weigh 10 g of 0.13PYN - 0.39PZ - 0.48PT ceramic powder and put it into a mortar. Add 1 ml of 5 wt.% PVA aqueous solution for granulation, and the PVA aqueous solution is added dropwise in several times. Then pass it through a 200 - mesh sub - sample sieve to obtain the granulated powder. Weigh 0.55 g of the granulated powder and put it into a mold with a diameter of 10 mm for pressing. After pressing at a pressure of 10 Mpa and holding the pressure for 15 s, obtain the green sheet. Put the green sheet into a muffle furnace and heat it up to 600 °C at a heating rate of 2 °C / min and keep it at this temperature for 2 hours to remove the binder. The binder - removed green sheet is put into a muffle furnace in a buried - firing manner and heated up to 1000 °C at a heating rate of 5 °C / min, and then heated up to 1200 °C at a heating rate of 3 °C / min. Keep it at this temperature for 2 hours to obtain the 0.13PYN - 0.39PZ - 0.48PT ceramic sheet.

[0110] A 0.13PYN-0.39PZ-0.48PT ceramic sheet was polished with sandpaper to a smooth, uniform surface of 0.7mm. Silver paste was then evenly applied to the upper and lower surfaces of the sheet. The sheet was then placed in a muffle furnace and heated to 560°C at a rate of 5°C / min for 20 minutes to produce a sheet with silver electrodes. Excess silver was removed from the edges using sandpaper. The sheet was then polarized in a 120°C silicone oil bath at 40kV / cm for 30 minutes to produce a piezoelectric ceramic with macroscopic piezoelectric properties.

[0111] Comparative Example 2:

[0112] A manganese carbonate doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic, the chemical composition of which is 0.4wt.% MnCO3-0.13Pb(Yb 0.5 Nb 0.5 )O3-0.39PbZrO3-0.48PbTiO3; its preparation method is as follows:

[0113] (1) 14.7795 g of Yb2O3 (99.99%) and 9.9779 g of Nb2O5 (99.9%) were weighed and placed in a ball mill. The mixture was ball milled at 200 r / min on a horizontal ball mill for 12 h. The mixture was then dried at 80°C. The dried powder was transferred to a crucible and sintered at 1200°C for 2 h to obtain the precursor YbNbO4.

[0114] (2) According to 0.4wt.%MnCO3-0.13Pb(Yb 0.5 Nb 0.5 )O3-0.39PbZrO3-0.48PbTiO3 stoichiometric ratios were obtained. 2.1457g of YbNbO4, 0.1381g of MnCO3, 23.2349g of PbO (99.9%), 4.8061g of ZrO2 (99.99%), and 3.8341g of TiO2 (99.99%) were weighed and placed in a ball mill. 30ml of anhydrous ethanol was added and the mixture was milled in a horizontal ball mill at 200 rpm for 12 hours. After thorough milling, the mixture was dried in an oven at 80°C.

[0115] (3) The dried mixed powder was ground and placed in a corundum crucible for compaction. The crucible was then transferred to a muffle furnace and heated to 850°C at a heating rate of 5°C / min. After being kept at this temperature for two hours, it was cooled to room temperature to obtain 0.4 wt.% MnCO3-0.13Pb(Yb 0.5 Nb 0.5)Pre-sintered powder of 0.4wt.%MnCO3-0.13Pb(Yb

[0116] (4) Weigh 10 grams of 0.4wt.%MnCO3-0.13Pb(Yb 0.5 Nb 0.5 )O3-0.39PbZrO3-0.48PbTiO3 ceramic powder and put it into a mortar. Add 1 ml of 5wt.% PVA aqueous solution for granulation, and the PVA aqueous solution is added dropwise in several times. Then pass through a 200-mesh sample sieve to obtain granulated powder. Weigh 0.55 g of the granulated powder and put it into a mold with a diameter of 10 mm for pressing. Under a pressure of 10 Mpa, after holding the pressure for 15 s, a green body sheet is obtained. The green body sheet is put into a muffle furnace and heated to 600 °C at a heating rate of 2 °C / min, and held for 2 hours to remove the binder. The degreased green body sheet is put into the muffle furnace in a buried firing method and heated to 1000 °C at a heating rate of 5 °C / min, and then heated to 1200 °C at a heating rate of 3 °C / min and held for 2 hours to obtain 0.4wt.%MnCO3-0.13Pb(Yb 0.5 Nb 0.5 )O3-0.39PbZrO3-0.48PbTiO3 ceramic sheet.

[0117] Use sandpaper to polish the 0.4wt.%MnCO3-0.13Pb(Yb 0.5 Nb 0.5 )O3-0.39PbZrO3-0.48PbTiO3 ceramic sheet to a thickness of 0.7 mm, and the surface is smooth and uniform. Then evenly brush silver paste on the upper and lower surfaces of the ceramic sheet, and then put it into a muffle furnace and heat it to 560 °C at a heating rate of 5 °C / min and hold for 20 minutes to obtain a ceramic sheet with silver electrodes. Use sandpaper to remove the excess silver layer on the edge, and then polarize it in a 120 °C silicone oil bath under an electric field of 40 kV / cm for 30 minutes to obtain a piezoelectric ceramic with macroscopic piezoelectric properties.

[0118] Test examples:

[0119] After placing the piezoelectric ceramics prepared in Examples 1-3 and Comparative Examples 1-2 for 24 hours respectively, electrical tests are carried out. The test results are shown in Table 1.

[0120] Table 1 Electrical property tests of Examples 1-3 and Comparative Examples 1-2

[0121]

[0122] Note: The temperature coefficient of resonance frequency in the table is the temperature coefficient of resonance frequency from 20 °C to 80 °C.

[0123] As can be seen from Table 1, compared with Comparative Example 1, the piezoelectric coefficient decreases, the mechanical quality factor is nearly 30 times higher, and the Curie temperature, the temperature stability coefficient of the resonance frequency, and the coercive field have small differences, while the remanent polarization intensity differs by half. Compared with Comparative Example 2, Examples 1 to 3 have similar piezoelectric coefficients, the mechanical quality factor is nearly 5 times higher, the Curie temperature and the resonance frequency stability coefficient have little difference, the remanent polarization intensity is close, but the coercive field has a large difference.

[0124] The ceramic phase structure prepared in Example 2 was measured by X-ray diffraction, as Figure 1 shown. It can be seen from the figure that the piezoelectric ceramic prepared in Example 2 of the present invention has a pure perovskite structure.

[0125] The microstructure of the prepared ceramic was measured by SEM, as Figure 2 shown. It can be seen from the figure that the average grain diameter of the piezoelectric ceramic prepared in Example ② of the present invention is 0.58 μm.

[0126] From Figure 3 the graph of the relative dielectric constant and dielectric loss varying with temperature, it can be seen that the Curie temperature of the piezoelectric ceramic prepared in Example 2 of the present invention is 363 °C, the relative dielectric constant at room temperature is 920, and the maximum relative dielectric constant is 12500.

[0127] From Figure 4 the graph of the polarization intensity varying with the electric field, it can be seen that the remanent polarization intensity of the piezoelectric ceramic prepared in Example 2 of the present invention is 11.4 μc / cm 2 , and the coercive field is 12 kV / cm.

[0128] Figure 5 is the impedance spectrum of the piezoelectric ceramic material prepared in Example 2. According to Figure 5 the resonance and anti-resonance frequencies, through the formula

[0129] 1 / k p 2 = 0.398*f r / (f a -f r ) + 0.579

[0130] the planar electromechanical coupling coefficient k of the piezoelectric ceramic prepared in Example 2 of the present invention is calculated to be p = 0.51.

[0131] Figure 6 is the graph of the resonance frequency and electromechanical coupling coefficient of the piezoelectric ceramic material prepared in Example 2 of the present invention varying with temperature. According to Figure 6 the resonance frequency and electromechanical coupling coefficient k pThe temperature variation diagram shows that the piezoelectric ceramic prepared in Example 2 of the present invention has a resonant frequency temperature coefficient of -223 ppm / °C and an electromechanical coupling coefficient temperature coefficient of 299 ppm / °C at 20°C to 80°C.

[0132] In summary, the MnN-PYN-PZT piezoelectric ceramics prepared in this invention effectively address key technical challenges in the fabrication of high-power devices, namely, meeting the performance requirements of high Curie temperature, high mechanical quality factor, high piezoelectric coefficient, high electromechanical coupling coefficient, and high temperature stability. Furthermore, they effectively avoid the potential generation of pyrochlore impurities in Mn-doped ceramics. Therefore, the MnN-PYN-PZT piezoelectric ceramics of this invention are a highly promising candidate material for developers of high-power devices.

[0133] The above description is merely a preferred embodiment of the present invention, and the present invention is not limited to the above embodiment. It is understood that other improvements and variations directly derived or imagined by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the scope of protection of the present invention.

Claims

1. A lead zirconate titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate, characterized in that, The chemical formula of the manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic is: x wt.%MnNbO4- y Pb(Yb 0.5 Nb 0.5 )O3- z PbZrO3-(1- y - z )PbTiO3, where 1.4 ≤ x ≤ 1.8, 0.1 ≤ y ≤ 0.14, 0.37 ≤ z ≤ 0.42; The preparation method of the manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic comprises the following steps: (1) Mix the YbNbO4 precursor, MnNbO4 precursor, TiO2, ZrO2, and PbO according to x wt.% MnNbO4 - y Pb(Yb 0.5 Nb 0.5 )O3 - z PbZrO3 - (1 - y - z )PbTiO3, where 1.4 ≤ x ≤ 1.8, 0.1 ≤ y ≤ 0.14, 0.37 ≤ z ≤ 0.

42. After proportioning, ball mill evenly to obtain a mixture. After drying, grind to obtain a ground material; (2) Pre-sinter the abrasive to obtain a pre-sintered powder with a pure perovskite phase, and then perform secondary ball milling and drying to obtain a dried powder; (3) Granulate, screen, and press the dried powder into a green sheet. After debinding the green sheet, sinter it to obtain the manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic; In step (1), the preparation method of the YbNbO4 precursor is as follows: According to the chemical formula of YbNbO4, weigh the raw materials Yb2O3 and Nb2O5. After mixing Yb2O3 and Nb2O5, perform ball milling, then drying treatment, grinding, and calcination to obtain the YbNbO4 precursor; The molar ratio of Yb2O3 to Nb2O5 is 1:1; the speed of the ball milling is 200-300 r / min, and the time is 8-12 h; the drying temperature is 80-100 °C, and the time is 3-4 h; the calcination temperature is 1200 °C - 1250 °C, and the time is 2-4 h; The preparation method of the MnNbO4 precursor is as follows: After mixing MnO2 and Nb2O5, perform ball milling, drying, grinding, and calcination to obtain the MnNbO4 precursor; The molar ratio of MnO2 to Nb2O5 is 1:1; the speed of the ball milling is 200-300 r / min, and the time is 8-12 h; the drying temperature is 80-100 °C, and the time is 3-4 h; the calcination temperature is 1100 °C - 1200 °C, and the time is 2-6 h; In step (2), the pre-sintering temperature is 850-900 °C, and the time is 2-2.5 h; For the sintering, heat the debound green sheet at a rate of 4-6 °C / min to 1000-1050 °C, then heat it at a rate of 2-4 °C / min to 1100-1200 °C. After holding for 2-4 h, cool it to room temperature at a rate of 4-6 °C / min.

2. The lead zirconate titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate according to claim 1, characterized in that, In step (1), the rotation speed of the ball milling is 200-300 r / min, and the time is 8-12 h; the drying temperature is 80-100 °C, and the time is 3-4 h.

3. The lead zirconate titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate according to claim 1, characterized in that, The time for the secondary ball milling is 8-12 h; the drying temperature is 80-100 °C, and the time is 2-4 h.

4. The lead zirconate titanate piezoelectric ceramic doped with manganese niobate and ytterbium niobate according to claim 1, characterized in that, In step (3), for the granulation, granulate the dried powder with an aqueous solution of polyvinyl alcohol. The mass-volume ratio of the dried powder to the aqueous solution of polyvinyl alcohol is 10-15 g:1 mL; the mass concentration of the aqueous solution of polyvinyl alcohol is 3-5%; the aperture of the sieve used for screening is 200 mesh; for the debinding treatment, heat the green sheet at a rate of 2-3 °C / min to 600-650 °C, hold for 2-3 h, and then cool it to room temperature at a rate of 5 °C / min.

5. The manganese niobate-doped lead ytterbium niobate-lead zirconate titanate piezoelectric ceramic described in claim 1 is used for high-power devices.

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