Piezoelectric single crystal combined polarization system and method in super-Curie temperature environment

Abstract

The invention discloses a piezoelectric single crystal combined polarization system in a super-Curie temperature environment, which comprises a silicone oil heating furnace for placing a piezoelectric material to be processed and performing controllable heating on the piezoelectric material. And the signal generation module is used for generating a corresponding electric field signal and applying the electric field signal to the piezoelectric material in the silicone oil heating furnace. And the monitoring module is used for monitoring the temperature and the voltage value in the silicone oil heating furnace. And the main control module is in signal connection with the signal generation module and the monitoring module, issues a control instruction to the signal generation module, and monitors the temperature and the voltage in real time. The alternating-current and direct-current combined electric field is output through the signal generator, the electric field is applied when the temperature of the sample is close to the Curie temperature, the domain structure of the sample is effectively optimized, and the polarization effect is remarkably improved. A temperature control device is arranged in the silicone oil heating furnace, so that the polarization uniformity and the domain structure stability are further improved. Real-time monitoring and data analysis are carried out, and the polarization effect of the sample is quantitatively evaluated.

Description

Technical Field

[0001] The present invention belongs to the field of domain engineering polarization of piezoelectric single crystal materials, and in particular relates to a joint polarization system and method for a piezoelectric single crystal in a super-Curie temperature environment. Background Art

[0002] Piezoelectric single crystals, represented by Pb(Mg1 / 3Nb2 / 3)O3-PbTiO3 (PMN-PT) relaxor ferroelectric single crystals, are an extremely important type of functional material that can realize the conversion between mechanical energy and electrical energy. Compared with traditional piezoelectric ceramic materials, piezoelectric single crystals have ultra-high piezoelectric coefficients, excellent electromechanical coupling coefficients, and lower dielectric losses, showing unique technical advantages. With these excellent properties, relaxor ferroelectric single crystals have quickly become the core material in key electronic devices such as underwater acoustic transducers, ultrasonic transducers, precision actuators, resonators, etc., and are widely used in industry, medical care, aerospace, military and other fields, making important contributions to the national economy and national defense construction.

[0003] In recent years, with the growing demand for piezoelectric single crystal materials, the research on high-performance piezoelectric single crystals has gradually become a research hotspot in the field of materials science. The key to promoting the development of piezoelectric single crystal technology is to develop new single crystal materials with higher stability and better performance, optimize the piezoelectric, dielectric and electromechanical coupling properties of existing materials, and deeply reveal the mechanism of performance optimization.

[0004] At present, a variety of performance optimization methods have been developed around piezoelectric single crystals, including exploring more solid solution systems and regulating lattice defects through doping. However, these methods usually require changing the composition of the material or the manufacturing process, which is complicated and costly to operate, limiting their widespread application. Based on this, the domain engineering technology developed in recent years provides an efficient and low-cost means of performance optimization. Engineering technology uses post-processing methods to regulate the internal domain structure of the material without changing the chemical composition of the ferroelectric material, so as to achieve precise control of the dielectric and piezoelectric properties of the piezoelectric single crystal.

[0005] Among them, AC polarization and field cooling polarization, as typical application methods of domain engineering technology, have attracted widespread attention due to their remarkable effects in improving the performance of piezoelectric single crystals. AC polarization makes the domain structure of the material more uniform by periodically changing the polarization electric field, thereby significantly improving the electromechanical properties of the material; while field cooling polarization applies an electric field to the material near the Curie temperature and slowly cools it to rearrange the domain structure, thereby effectively improving the piezoelectric coefficient and other key performance indicators. These methods have significant advantages such as a wide range of applicable materials, significant performance improvement effects, simple operation and low cost, and are gradually becoming a hot spot in domain engineering research.

[0006] However, there are still deficiencies in the current research on the joint polarization method in super-Curie temperature environments. Especially in piezoelectric single crystals, the specific mechanism of field cooling polarization and its impact on material properties have not been deeply studied. In addition, how to combine AC polarization with field cooling polarization to further explore its potential in domain structure regulation and performance improvement is still a scientific problem that needs to be solved. This patent proposes an innovative joint polarization system and method in a super-Curie temperature environment, which provides a new technical path for optimizing the comprehensive performance of piezoelectric single crystals. Summary of the invention

[0007] The technical purpose of the present invention is to provide a system and method for the joint polarization of a piezoelectric single crystal in a super-Curie temperature environment, so as to study the direction of joint polarization in a super-Curie temperature environment.

[0008] To solve the above problems, the technical solution of the present invention is: A joint polarization system of a piezoelectric single crystal in a super-Curie temperature environment, comprising: A silicone oil heating furnace is configured to place the piezoelectric material to be processed and perform controllable heating on the piezoelectric material. During the heating process, the ambient temperature of the piezoelectric material is maintained at a temperature required for polarization; A signal generating module is configured to generate a corresponding electric field signal and apply it to the piezoelectric material in the silicone oil heating furnace; wherein the electric field signal includes a direct current electric field signal and an alternating current electric field signal; The monitoring module is configured to monitor the temperature in the silicone oil heating furnace and the voltage value applied to the piezoelectric material by the signal generating module to obtain monitoring data; The main control module is respectively connected to the signal generating module and the monitoring module by signal, and is configured to issue control instructions to the signal generating module to control the signal generating module to generate a DC electric field signal or an AC electric field signal and control the voltage; it is also configured to receive monitoring data from the monitoring module to monitor the temperature and voltage in real time.

[0009] Wherein, the signal generation module includes a signal generator, a voltage amplifier, an upper electrode and a lower electrode; The signal generator is connected to the main control module by signal, and is configured to receive a control instruction issued by the main control module and generate an electric field signal based on the control instruction; The voltage amplifier is connected to the signal generator signal and is configured to amplify the amplitude of the electric field signal output by the signal generator; The upper electrode and the lower electrode are both connected to the output signal of the voltage amplifier, and the upper electrode and the lower electrode are respectively arranged on the upper and lower surfaces of the piezoelectric material, and are configured to apply the amplified electric field signal to the piezoelectric material.

[0010] Among them, the signal generator and the silicone oil heating furnace cooperate with each other to generate the corresponding electric field signal, specifically: When the silicone oil heating furnace heats the piezoelectric material to the Curie temperature, the signal generator generates an AC electric field signal to pre-polarize the piezoelectric material so that the domain structure is initially arranged; When the silicone oil heating furnace heats the piezoelectric material at a constant temperature, the signal generator generates a DC electric field signal to realize DC polarization of the piezoelectric material, so that the domain structure is further oriented; After polarization is completed, through field cooling, the signal generator continuously generates a DC electric field signal during the temperature drop process to solidify the domain structure.

[0011] Specifically, the monitoring module includes a first voltage probe, a second voltage probe and an oscilloscope; The first voltage probe is connected to the upper electrode signal and is configured to monitor the voltage value at the upper electrode in real time; the second voltage probe is connected to the lower electrode signal and is configured to monitor the voltage value at the lower electrode in real time; The oscilloscope is respectively connected to the output end of the first voltage probe and the output end of the second voltage probe, and is configured to receive voltage value related signals from the first voltage probe and the second voltage probe, and then record the voltage value change curve and feed back the data to the main control module.

[0012] Further preferably, the monitoring module also includes a temperature probe configured to monitor the temperature of the piezoelectric material in real time and feed back the temperature data to the main control module.

[0013] Among them, the main control module adopts a computer, and the main control module will also adaptively adjust the electric field signal of the signal generating module and the heating temperature of the silicone oil heating furnace according to the monitoring data of the monitoring module.

[0014] A method for joint polarization of a piezoelectric single crystal in a super-Curie temperature environment, adapted to the joint polarization system of a piezoelectric single crystal in a super-Curie temperature environment as described above, comprises the following steps: The piezoelectric material is placed in a silicone oil heating furnace and gradually heated to a temperature close to the Curie temperature; Applying an alternating electric field through a signal generator to pre-polarize the piezoelectric material, so that the internal domain structure of the piezoelectric material is initially arranged; Under the condition of keeping the temperature constant, switch to a DC electric field to DC polarize the piezoelectric material and further control the domain structure; After DC polarization is completed, the DC electric field is maintained by field cooling during the cooling process to solidify the domain structure; When the temperature drops to room temperature, stop applying the electric field, take out the polarized piezoelectric material, and complete the domain engineering polarization operation; Among them, the electric field and temperature data are monitored, and the electric field strength and temperature changes during the polarization process are recorded by a voltage probe, an oscilloscope, and a temperature probe.

[0015] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: The present invention realizes the application of AC and DC combined electric field, outputs the AC and DC combined electric field through a signal generator, and applies the electric field when the sample temperature is close to the Curie temperature, effectively optimizing the domain structure of the sample and significantly improving the polarization effect; The silicone oil heating furnace is equipped with a temperature control device, which is combined with the field cooling process. After the temperature control device heats the sample temperature to the Curie temperature range, the system realizes temperature field cooling by gradual cooling while maintaining the electric field application, further improving the polarization uniformity and the stability of the domain structure. Real-time monitoring and data analysis: Through the coordinated work of voltage probes, oscilloscopes and temperature probes, the system can monitor the electric field, voltage and temperature data in real time to ensure that the polarization process is stable and controlled. The data is summarized and analyzed by a computer to quantitatively evaluate the polarization effect of the sample; Improve sample performance: Through the polarization method provided by the present invention, the piezoelectric constant, mechanical quality factor and other performance indicators of the sample are significantly improved, especially in high-power application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the following detailed description of the preferred embodiment.The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting the invention.

[0017] Figure 1 It is a structural block diagram of the joint polarization system of the piezoelectric single crystal in the super-Curie temperature environment of the present invention; Figure 2 It is a structural block diagram of the joint polarization method of a piezoelectric single crystal in a super-Curie temperature environment of the present invention; Figure 3 It is a schematic flow chart of the joint polarization method of a piezoelectric single crystal in a super-Curie temperature environment of the present invention; Figure 4 A comparison diagram of the relative free dielectric constant of the piezoelectric single crystal after joint polarization and DC polarization of the present invention; Figure 5 This is a comparison diagram of the piezoelectric strain constant of the piezoelectric single crystal after joint polarization and DC polarization of the present invention.

[0018] Description of Reference Numerals 101: main control module; 102: signal generator; 103: voltage amplifier; 104: upper electrode; 105: piezoelectric material; 106: lower electrode; 107: silicone oil heating furnace; 108: first voltage probe; 109: oscilloscope; 110: second voltage probe; 111: temperature probe. DETAILED DESCRIPTION

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0020] In order to simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0021] The following is a further detailed description of a joint polarization system and method for a piezoelectric single crystal under a super-Curie temperature environment proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0022] Piezoelectric single crystal materials, especially Pb(Mg1 / 3Nb2 / 3)O3-PbTiO3 (PMN-PT) relaxor ferroelectric single crystals, have become an extremely important functional material due to their excellent performance and are widely used in the field of efficient conversion of mechanical energy and electrical energy. Compared with traditional piezoelectric ceramics, piezoelectric single crystals have higher piezoelectric constants, better electromechanical coupling performance and lower dielectric loss. They have become the core materials of electronic devices such as underwater acoustic transducers, ultrasonic transducers and precision actuators, and play a key role in the fields of medicine, industry, aerospace and national defense.

[0023] With the increasing demand for high-performance piezoelectric single crystals, methods to optimize the performance of piezoelectric single crystals have gradually become a research focus. At present, performance optimization is mainly achieved through doping regulation, composition adjustment, and solid solution system exploration. However, these methods often require changes in the composition structure of the material, and the process is complex and costly, making it difficult to achieve large-scale promotion and application.

[0024] In response to the above problems, domain engineering technology has developed rapidly in recent years, providing a new way to optimize the performance of piezoelectric single crystals at low cost. Domain engineering technology can effectively improve the piezoelectric and dielectric properties by regulating the domain structure of the material through the application of external electric field and temperature field without changing the chemical composition of the material. Among them, AC polarization and field cooling polarization are typical domain engineering methods.

[0025] AC polarization makes the domain structure more uniform through the action of periodic electric field, which helps to improve the electromechanical properties of the material; field cooling polarization applies an electric field when the material is close to the Curie temperature, and uses a slow cooling process to cause the domain structure to rearrange, significantly improving the piezoelectric constant and mechanical properties. These methods are simple to operate, low-cost, and have the potential for wide application.

[0026] However, the current research on the combined polarization method under Curie temperature environment is still insufficient. Especially in piezoelectric single crystals, the specific mechanism of field cooling polarization and its influence on material properties have not been studied in depth. In addition, how to combine AC polarization with field cooling polarization to further explore its potential in domain structure regulation and performance improvement is still a scientific problem that needs to be solved urgently.

[0027] Therefore, it is very important to explore the optimal polarization parameters of piezoelectric vibrator single crystal materials by optimizing and combining various domain structure polarization methods, in order to optimize the performance of piezoelectric vibrator single crystal materials and expand the practical application of piezoelectric single crystals.

[0028] Example See also Figures 1 to 5 Based on the above background, this embodiment provides a joint polarization system for piezoelectric single crystals in a super-Curie temperature environment, which mainly includes the following parts: a silicone oil heating furnace 107, a signal generating module, a monitoring module and a main control module 101. The silicone oil heating furnace 107 is used to place the piezoelectric material 105 to be processed and perform controllable heating on the piezoelectric material 105. During the heating process, the ambient temperature of the piezoelectric material 105 is maintained at the temperature required for polarization. The signal generating module is used to generate a corresponding electric field signal and apply it to the piezoelectric material 105 in the silicone oil heating furnace 107; wherein the electric field signal includes a DC electric field signal and an AC electric field signal. The monitoring module is used to monitor the temperature in the silicone oil heating furnace 107, and to monitor the voltage value applied to the piezoelectric material 105 by the signal generating module to obtain monitoring data. The main control module 101 is respectively connected to the signal generating module and the monitoring module by signal, and is configured to issue control instructions to the signal generating module to control the signal generating module to generate a DC electric field signal or an AC electric field signal and control the voltage; it is also used to receive monitoring data from the monitoring module to monitor the temperature and voltage in real time.

[0029] See also Figure 1The main control module 101 uses a computer. The main control module 101 can control the operation of each module in the system, set polarization parameters through the main control module 101, and record and analyze various data in the polarization process in real time. Specifically, it can simultaneously collect data from the oscilloscope 109 and the temperature probe 111 for analysis and recording.

[0030] See also Figure 1 The signal generating module includes a signal generator 102 , a voltage amplifier 103 , an upper electrode 104 and a lower electrode 106 .

[0031] The signal generator 102 is connected to the main control module 101 by signal, and is used to receive the control instructions issued by the main control module 101, and then generate the AC and DC electric field signals required for DC combined polarization based on the control instructions. The amplitude and frequency of the electric field can be adjusted according to the experimental requirements. Preferably, the signal generator 102 can output AC and DC combined electric fields of different amplitudes and frequencies according to the set parameters to meet the requirements of different materials and polarization processes. The selection of electric field amplitude and frequency depends on the physical properties of the material, the polarization efficiency requirements, and the thermo-electric behavior. Taking PMN-30PT material as an example, the AC electric field parameters of AC and DC combined polarization can be set to a symmetrical triangular wave with an amplitude of 7.5 kV / cm and a frequency of 0.1 Hz, and a total of 10 cycles are applied; the DC electric field is 7.5kV / cm, and the electric field is continuously applied while the sample is cooled to room temperature. This parameter setting can effectively optimize the polarization effect, improve the dielectric and piezoelectric properties of the material, and avoid sample damage caused by electric field or temperature changes.

[0032] The voltage amplifier 103 is signal-connected to the signal generator 102 and is used to amplify the amplitude of the electric field signal output by the signal generator 102 to ensure that the electric field intensity acting on the piezoelectric material 105 meets the polarization condition.

[0033] The upper electrode 104 and the lower electrode 106 are both connected to the output signal of the voltage amplifier 103, and the upper electrode 104 and the lower electrode 106 are respectively arranged on the upper and lower surfaces of the piezoelectric material 105, for uniformly applying the electric field to the surface of the piezoelectric single crystal sample, ensuring that the electric field is uniformly distributed inside the sample and realizing a stable polarization process.

[0034] Among them, a temperature control device is provided in the silicone oil heating furnace 107, through which the temperature of the sample is heated to the Curie temperature. For example, for PMN-30PT relaxor ferroelectric material, its Curie temperature is 131°C. Then, the temperature is gradually reduced according to the preset cooling rate. The selection of the cooling rate needs to comprehensively consider the thermal stability and microstructural changes of the material to avoid problems such as stress concentration or cracking of the sample caused by too fast cooling speed. For PMN-30PT material, the cooling rate should be controlled below 3°C / min to ensure the stability of the cooling process and reduce the influence of thermal stress on the structural integrity of the sample, thereby improving the reliability and consistency of the polarization effect. While the temperature changes, the signal generator 102 will cooperate with the temperature change in the silicone oil heating furnace 107 to generate a corresponding electric field signal, specifically: when the piezoelectric material 105 is heated to the Curie temperature in the silicone oil heating furnace 107, the signal generator 102 generates an AC electric field signal to pre-polarize the piezoelectric material 105 so that the domain structure is initially arranged. When the silicone oil heating furnace 107 heats the piezoelectric material 105 at a constant temperature, the signal generator 102 generates a DC electric field signal to achieve DC polarization of the piezoelectric material 105, so that the domain structure is further oriented. After the polarization is completed, the temperature is gradually reduced from the Curie temperature range at a set rate through field cooling, and in this process, the signal generator 102 continuously generates a DC electric field signal, which is conducive to the precise control and stable formation of the domain structure.

[0035] Specifically, the monitoring module includes a first voltage probe 108, a second voltage probe 110 and an oscilloscope 109. The first voltage probe 108 is connected to the upper electrode 104 for real-time monitoring of the voltage value at the upper electrode 104; the second voltage probe 110 is connected to the lower electrode 106 for real-time monitoring of the voltage value at the lower electrode 106. The oscilloscope 109 is connected to the output end of the first voltage probe 108 and the output end of the second voltage probe 110 for receiving voltage value related signals from the first voltage probe 108 and the second voltage probe 110, and then displays and records the voltage value change curve and feeds the data back to the main control module 101. In this way, the stability and accuracy of the electric field application are ensured, and the error in the polarization process is reduced.

[0036] Preferably, the monitoring module further includes a temperature probe 111 for real-time monitoring of the temperature of the piezoelectric material 105 and feeding back the temperature data to the main control module 101 to ensure accurate temperature control. Preferably, the main control module 101 can dynamically adjust the output power of the temperature control device through the real-time temperature data fed back by the temperature probe 111 to ensure that the temperature of the sample is always within a preset range.

[0037] Therefore, the system of this embodiment outputs the electric field through the coordinated output of the signal generator 102 and the voltage amplifier 103, and cooperates with the temperature control device to realize the field cooling polarization process of the sample within the Curie temperature range. The voltage probe and oscilloscope 109 are used to monitor the electric field changes in real time, and the temperature probe 111 accurately controls the temperature conditions. Finally, the computer collects and analyzes data to evaluate the polarization effect and domain structure regulation performance of the sample. The specific analysis and evaluation implementation method includes: using an impedance analyzer to measure the dielectric properties of the sample, such as the dielectric constant and loss factor, to quantify the changes in the dielectric properties of the material during the polarization process; at the same time, using a quasi-static piezoelectric constant measuring instrument to test the piezoelectric properties of the sample, such as the piezoelectric constant , thus fully characterizing the improvement and optimization of the piezoelectric properties of the samples by the polarization effect. These test results provide a key basis for verifying the effectiveness of the polarization process and improving material properties.

[0038] Preferably, see Figure 2 and Figure 3 This embodiment also provides a method for joint polarization of a piezoelectric single crystal in a super-Curie temperature environment, adapted to the joint polarization system of a piezoelectric single crystal in a super-Curie temperature environment as described above, comprising the following steps: The piezoelectric material 105 is placed in a silicone oil heating furnace 107 and gradually heated to a temperature close to the Curie temperature. An AC electric field is applied by a signal generator 102 to pre-polarize the piezoelectric material 105 so that the internal domain structure of the piezoelectric material 105 is preliminarily arranged. While maintaining a constant temperature, switch to a DC electric field to DC polarize the piezoelectric material 105 to further regulate the domain structure. After the DC polarization is completed, the DC electric field is maintained by field cooling during the cooling process to solidify the domain structure. When the temperature drops to room temperature, stop applying the electric field, take out the polarized piezoelectric material 105, and complete the domain engineering polarization operation. Among them, the electric field and temperature data are monitored, and the electric field strength and temperature changes during the polarization process are recorded by a voltage probe, an oscilloscope 109, and a temperature probe 111. The above method can effectively optimize the domain structure of the piezoelectric single crystal and improve its dielectric, piezoelectric and electromechanical coupling properties through AC / DC combined polarization and field cooling processes.

[0039] Now, in combination with the above system and method, the operation process of this embodiment is described: First, sample preparation and system initialization: The piezoelectric single crystal sample to be polarized is placed between the upper electrode 104 and the lower electrode 106 to ensure that the electrodes are in full contact with the sample surface to achieve application of a uniform electric field.

[0040] Start the temperature control device and set the system temperature parameters to the Curie temperature range of the sample.

[0041] The parameters of the signal generator 102, the voltage amplifier 103 and the temperature control device are initialized by the main control module 101, including the electric field type (DC, AC or AC / DC combined electric field), electric field amplitude, frequency, temperature control heating rate and cooling rate, etc.

[0042] Then, heat to the Curie temperature: The temperature control device starts the heating function to regulate the temperature of the sample.

[0043] The temperature probe 111 monitors the temperature change of the sample in real time and feeds the data back to the computer to ensure that the temperature gradually rises to the set Curie temperature range.

[0044] When the sample temperature approaches the Curie temperature, the system is kept at a constant temperature and ready for the application of the electric field.

[0045] Next, a combined AC and DC electric field is applied: The signal generator 102 is started to output a preset AC / DC combined electric field signal, and the voltage is amplified to a set level through the voltage amplifier 103 .

[0046] The electric field is uniformly applied to the piezoelectric material 105 through the upper electrode 104 and the lower electrode 106 .

[0047] The voltage probe and oscilloscope 109 monitor the voltage changes of the upper and lower electrodes 106 in real time, calculate the electric field strength using the distance between the upper and lower electrodes 106, ensure the stability and accuracy of the electric field application, and transmit the data to the computer for recording and analysis.

[0048] Entering the field cooling process: While maintaining the electric field application, the temperature of the piezoelectric material 105 is gradually reduced.

[0049] The temperature control device controls the temperature to gradually decrease according to the set cooling rate. The temperature probe 111 monitors the sample temperature in real time and feeds the data back to the computer to ensure that the temperature decreases steadily according to the preset curve.

[0050] The voltage probe and oscilloscope 109 continue to monitor the electric field response of the sample and record the voltage data and electric field distribution in real time.

[0051] At the same time, data collection and analysis are carried out: During the entire polarization process, the computer receives and records the monitoring data of the temperature probe 111, the voltage probe and the oscilloscope 109 in real time, including parameters such as temperature curve, electric field strength, and voltage change.

[0052] After the polarization process is completed, the computer analyzes the collected data to evaluate the domain structure changes, polarization effects and performance parameters of the samples.

[0053] Finally, the system stops with the sample test: When the temperature control device cools down to room temperature and the electric field application ends, the system automatically stops running.

[0054] Take out the polarized samples and conduct further performance testing and analysis to verify the improvement effect of the piezoelectric performance of the samples, such as Figure 4 and Figure 5 shown.

[0055] Through the above operation process, the system of this embodiment performs precise domain engineering polarization on the sample under Curie temperature environment conditions through AC and DC combined electric fields, thereby optimizing the domain structure of the sample and improving the piezoelectric performance. At the same time, through the data monitoring and analysis function of the system, the polarization process can be accurately controlled and evaluated, thereby improving the stability and repeatability of the polarization effect.

[0056] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A joint polarization system of a piezoelectric single crystal in a super-Curie temperature environment, characterized in that: include: A silicone oil heating furnace is configured to place the piezoelectric material to be processed and perform controllable heating on the piezoelectric material. During the heating process, the ambient temperature of the piezoelectric material is maintained at a temperature required for polarization; A signal generating module is configured to generate a corresponding electric field signal and apply it to the piezoelectric material in the silicone oil heating furnace; wherein the electric field signal includes a direct current electric field signal and an alternating current electric field signal; A monitoring module is configured to monitor the temperature in the silicone oil heating furnace and the voltage value applied to the piezoelectric material by the signal generating module to obtain monitoring data; The main control module is respectively connected to the signal generating module and the monitoring module by signal, and is configured to issue control instructions to the signal generating module to control the signal generating module to generate a DC electric field signal or an AC electric field signal and control the voltage; it is also configured to receive monitoring data from the monitoring module to monitor the temperature and voltage in real time.

2. The joint polarization system of a piezoelectric single crystal under super-Curie temperature environment according to claim 1, characterized in that: The signal generation module includes a signal generator, a voltage amplifier, an upper electrode and a lower electrode; The signal generator is connected to the main control module by signal, and is configured to receive a control instruction issued by the main control module, and generate an electric field signal based on the control instruction; The voltage amplifier is signal-connected to the signal generator and is configured to amplify the amplitude of the electric field signal output by the signal generator; The upper electrode and the lower electrode are both connected to the output signal of the voltage amplifier, and the upper electrode and the lower electrode are respectively arranged on the upper and lower surfaces of the piezoelectric material, and are configured to apply the amplified electric field signal to the piezoelectric material.

3. The combined polarization system of a piezoelectric single crystal under super-Curie temperature environment according to claim 2, characterized in that: The signal generator and the silicone oil heating furnace cooperate with each other to generate a corresponding electric field signal, specifically: When the silicone oil heating furnace heats the piezoelectric material to the Curie temperature, the signal generator generates an AC electric field signal to pre-polarize the piezoelectric material so that the domain structure is preliminarily arranged; When the silicone oil heating furnace heats the piezoelectric material at a constant temperature, the signal generator generates a DC electric field signal to achieve DC polarization of the piezoelectric material, so that the domain structure is further oriented; After polarization is completed, the signal generator continuously generates a DC electric field signal through field cooling during the temperature drop process to solidify the domain structure.

4. The joint polarization system of a piezoelectric single crystal under super-Curie temperature environment according to claim 2, characterized in that: The monitoring module includes a first voltage probe, a second voltage probe and an oscilloscope; The first voltage probe is connected to the upper electrode signal and is configured to monitor the voltage value at the upper electrode in real time; The second voltage probe is connected to the lower electrode signal and is configured to monitor the voltage value at the lower electrode in real time; The oscilloscope is respectively connected to the output end of the first voltage probe and the output end of the second voltage probe, and is configured to receive voltage value related signals from the first voltage probe and the second voltage probe, and then record the voltage value change curve and feed back the data to the main control module.

5. The joint polarization system of a piezoelectric single crystal in a super-Curie temperature environment according to claim 1, characterized in that: The monitoring module also includes a temperature probe configured to monitor the temperature of the piezoelectric material in real time and feed back the temperature data to the main control module.

6. The joint polarization system of a piezoelectric single crystal in a super-Curie temperature environment according to claim 1, characterized in that: The main control module adopts a computer, and the main control module can also adaptively adjust the electric field signal of the signal generating module and the heating temperature of the silicone oil heating furnace according to the monitoring data of the monitoring module.

7. A method for joint polarization of a piezoelectric single crystal in a super-Curie temperature environment, adapted to the joint polarization system of a piezoelectric single crystal in a super-Curie temperature environment as claimed in any one of claims 1 to 6, characterized in that: The steps include: The piezoelectric material is placed in a silicone oil heating furnace and gradually heated to a temperature close to the Curie temperature; Applying an alternating electric field through a signal generator to pre-polarize the piezoelectric material, so that the internal domain structure of the piezoelectric material is initially arranged; Under the condition of keeping the temperature constant, switch to a DC electric field to DC polarize the piezoelectric material and further control the domain structure; After DC polarization is completed, the DC electric field is maintained by field cooling during the cooling process to solidify the domain structure; When the temperature drops to room temperature, stop applying the electric field, take out the polarized piezoelectric material, and complete the domain engineering polarization operation; Among them, the electric field and temperature data are monitored, and the electric field strength and temperature changes during the polarization process are recorded by a voltage probe, an oscilloscope, and a temperature probe.

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