Ultrathin stainless steel flexible substrate lead zirconate titanate-based piezoelectric-pyroelectric dual-functional double-sided thin-film sensor and its fabrication method

Abstract

This invention discloses an ultrathin stainless steel flexible substrate lead zirconate titanate-based piezoelectric-pyroelectric dual-functional double-sided thin-film sensor and its fabrication method. It mainly addresses the problems of lagging accuracy, potential damage to sealing during implantation, and limited functionality in existing technologies. It comprises: a substrate, lead zirconate titanate (Pb(Zr)) 0.52 Ti 0.48 The invention comprises an O3-xMO thin film layer, upper and lower electrode layers, wherein the substrate is made of flexible stainless steel and serves as both the substrate and the lower electrode layer; the thin film layer covers the upper and lower surfaces of the substrate, and the molar ratio x of the metal oxide MO doping is 0.001 to 0.05, formed by alternately spin-coating lead zirconate titanate sol gel on both sides of the substrate. This invention optimizes the stress distribution on both sides of the flexible substrate through a double-sided thin film structure, avoiding excessive bending and improving sensor stability. The use of doped oxides enhances the pyroelectric-piezoelectric properties of the thin film, making it suitable for in-situ safety monitoring of lithium-ion batteries.

Description

Technical Field

[0001] This invention belongs to the field of chemical materials technology, and in particular relates to a dual-function, double-sided thin-film sensor and its preparation method, which can be used for in-situ safety monitoring of lithium-ion batteries. Background Technology

[0002] High-capacity lithium-ion batteries (LIBs) are critical power sources widely used in portable electronic devices, electric vehicles (EVs), and renewable energy storage systems. To ensure their safe operation, real-time monitoring of internal battery signals for early fault diagnosis and warning is crucial. Unsafe batteries often exhibit abnormal changes in internal pressure and temperature during accidents. However, existing sensing devices suffer from limited accuracy, susceptibility to electrolyte chemical environments leading to failure, potential damage to the battery's sealing structure during implantation, and often limited functionality.

[0003] The stability, accuracy, and miniaturization of sensors are crucial for battery systems. Therefore, exploring easily integrated multi-parameter sensors has become an urgent research need. Among numerous sensing parameters, pressure and temperature are particularly critical. PZT materials, based on their ferroelectric properties, possess excellent intrinsic properties such as dielectric, piezoelectric, and pyroelectric activity. They also boast highly tunable composition, mature fabrication processes, and extensive application validation, thus exhibiting natural advantages in sensor fabrication. Against this backdrop, developing thin-film sensors capable of simultaneously monitoring temperature and pressure is of great significance for promoting the development of safe and high-performance batteries.

[0004] Patent document CN101481245A discloses a "Preparation Method of Nanocrystalline Lead Zirconate Titanate-Quartz Composite Structure Piezoelectric Sensing Material". The method involves preparing a PZT precursor sol, obtaining a dry gel through vacuum distillation, and then dissolving it in a mixture of ethylene glycol methyl ether, glycerol, and glacial acetic acid to form a PZT sol. This sol is then spin-coated onto a quartz substrate and heat-treated to obtain a thin film. Repeating spin-coating and heat treatment yields multiple thin films, which are then composited onto a quartz substrate to obtain a nanocrystalline PZT-quartz composite structure piezoelectric sensing material. However, since quartz may undergo phase transitions or softening above 500°C, while PZT crystallization requires 650–700°C, this can easily lead to substrate deformation or interfacial stress accumulation, reducing device reliability.

[0005] Patent document CN120249949A discloses "A lead zirconate titanate film material with ultra-high piezoelectric coefficient, its preparation method and application," which uses a sol-gel spin coating method and controls the number of annealing cycles to prepare the lead zirconate titanate film material. It exhibits high orientation, low coercivity, and excellent ferroelectric and piezoelectric properties, making it suitable for fabricating wafers large (2-4 inches), showing great application potential in the field of piezoelectric microelectromechanical systems (MEMS) devices. However, as advanced MEMS technology tends towards larger sizes (6-8 inches) or smaller nanoscale feature sizes, this process may encounter scaling uniformity issues over larger areas. Furthermore, it does not address compatibility with silicon-based CMOS processes and flexible substrates, limiting its application in monolithic integrated systems.

[0006] Patent document CN109761605 discloses "a lead zirconate titanate thin film with (100) preferred grain orientation and its preparation method," which prepares a lead zirconate titanate seed layer precursor solution with the chemical formula Pbx(ZryTi1-y)O3; then deposits it on a Pt / Ti / SiO2 / Si substrate, performs heat treatment, and then obtains an amorphous PZT thin film by radio frequency magnetron sputtering, thus obtaining a lead zirconate titanate thin film with (100) preferred orientation. However, the magnetron sputtering method has unavoidable high process risks, significant environmental burden, and low economic feasibility, which may increase costs and reduce yield in practical applications, limiting its promotion in sustainable manufacturing.

[0007] In summary, existing methods for fabricating sensing films face common challenges such as persistent reliability issues and cost and scalability limitations that restrict industrialization. More importantly, there is substrate dependence; that is, films are fabricated on hard substrates, such as Pt / Si or quartz. Thin-film sensors fabricated on such hard substrates cannot be used in complex scenarios such as in-situ battery safety monitoring, severely limiting their application scenarios.

[0008] Currently, battery safety monitoring applications primarily utilize grating + encapsulation layer / reinforcing FBG sensors, thin-film chip + PLC module / FPI-FBG cascaded WCFs sensors, and XRD-CT sensors. However, these sensors have various drawbacks. For example, grating + encapsulation layer / reinforcing FBG sensors can be damaged and implanted inside the battery, affecting the battery's structural sealing; thin-film chip + PLC module / FPI-FBG cascaded WCFs sensors lack high-temperature and high-pressure stability; and XRD-CT sensors with micro-focus sources and rotating detector stages are bulky and limited to offline laboratory analysis. More importantly, all of these monitoring sensors are integrated into external battery modules, leading to delayed monitoring and alarm times, which impacts battery safety. Therefore, there is an urgent need to develop a novel sensing film that combines a flexible multi-level structure to release substrate constraints with an intrinsic thermo-pressure coupling mechanism for non-destructive in-situ monitoring. This is a key path to overcome the technological barriers of early battery safety monitoring and ensure battery safety. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings of the prior art by providing an ultrathin stainless steel flexible substrate lead zirconate titanate-based piezoelectric-pyroelectric dual-function double-sided thin-film sensor and its fabrication method. This invention utilizes a sol-gel method to fabricate a highly stable multilayer composite film on an ultrathin flexible substrate, reducing production costs and improving the mass production capability of the sensor. While maintaining significant pyroelectric-piezoelectric performance, it non-invasively embeds the sensor into a battery, significantly advancing the alarm time in case of battery thermal-piezoelectric runaway and achieving advanced hazard warning capabilities.

[0010] To achieve the above objectives, the technical solution of the present invention includes:

[0011] 1. A piezoelectric-pyroelectric dual-function double-sided thin-film sensor based on an ultrathin stainless steel flexible substrate and lead zirconate titanate (Pb(Zr)) substrate, comprising: a substrate, lead zirconate titanate (Pb(Zr)) substrate, and lead zirconate titanate (Pb(Zr)) substrate. 0.52 Ti 0.48 O3-xMO) thin film layer, upper and lower electrode layers, characterized in that:

[0012] The substrate is made of flexible stainless steel and is used as both the substrate for the thin film and the lower electrode layer.

[0013] The thin film layer covers the upper and lower surfaces of the flexible stainless steel material to optimize the stress distribution on both sides of the substrate through a double-sided flexible structure, avoid excessive bending, and improve the stability of the sensor.

[0014] Preferably, the upper electrode layer is selected from any one of silver, silver-palladium alloy, platinum, copper or nickel.

[0015] Preferably, the metal oxide MO in the chemical formula of lead zirconate titanate is selected from one or a combination of copper oxide, bismuth oxide, lithium oxide, manganese oxide, and niobium oxide; x = 0.001 to 0.05 is the molar ratio of the doped oxide.

[0016] Preferably, the flexible stainless steel material has a thickness of 2-100 μm.

[0017] Preferably, the thickness of the thin film layer on the upper and lower surfaces of the stainless steel material is 200nm-10um.

[0018] 2. A method for fabricating an ultrathin stainless steel flexible substrate lead zirconate titanate-based piezoelectric-pyroelectric dual-functional double-sided thin-film sensor, characterized by comprising the following:

[0019] (1) Preparation of sol-gel:

[0020] The raw material Pb(CH3COOH)2·3H2O was dissolved in CH3COOH to obtain a solution containing Pb;

[0021] Zr(OC3H7)4 was dissolved in a mixed solvent of CH3COOH and CH3COCH2COCH3 to obtain a solution containing Zr.

[0022] Dissolving (Ti(OCH(CH3)2)4) in CH3COCH2COCH3 yields a solution containing Ti;

[0023] The three solutions were mixed, and then oxide MO was added. The mixture was stirred at 50-250℃ for 20-60 h and then left to stand for 50-90 h to obtain Pb(Zr) with a concentration of 0.01-0.8 M. 0.52 Ti 0.48 O3-xMO sol-gel, where MO is a metal oxide and x = 0.001 to 0.05 is the molar ratio of the doped oxide;

[0024] (2) Pb(Zr) 0.52 Ti 0.48 O3-xMO sol-gel was spin-coated onto one side of a clean, flexible stainless steel substrate and allowed to dry. Then, the sol-gel was spin-coated onto the other side and allowed to dry.

[0025] (3) The sample obtained in step (2) is pyrolyzed to simultaneously produce a monolayer of Pb(Zr) on both sides of the substrate. 0.52 Ti 0.48 O3-xMO sol-gel film was prepared and then annealed.

[0026] (4) Repeat steps (2) to (3) to obtain a bilayer Pb(Zr) with a total thickness of 200 nm to 10 μm. 0.52 Ti0.48 O3-xMO (i) composite thin film;

[0027] (5) Pt / Au / Ag top electrodes with a thickness of 300nm-500nm were sputtered on the upper and lower surfaces of the composite film using magnetron sputtering to complete the sensor fabrication.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] Firstly, this invention uses stainless steel as the substrate for a flexible sensor, enabling it to be implanted into complex structures without damage for safe monitoring.

[0030] Furthermore, this invention utilizes spin-coating of thin films of Pb(Zr) onto the upper and lower surfaces of a flexible substrate. 0.52 Ti 0.48 O3-xMO sol-gel can optimize the stress distribution on the substrate surface and improve device stability;

[0031] Third, by using a stainless steel substrate as the lower electrode, this invention reduces one lower electrode sputtering process, making the entire process more convenient.

[0032] Fourth, this invention uses Pb(Zr) doped with MO oxide. 0.52 Ti 0.48 Pb(Zr) sol-gel was spin-coated onto a stainless steel substrate. 0.52 Ti 0.48 O3-xMO thin films significantly improve the pyroelectric and piezoelectric properties of the films;

[0033] Fifth, the thin films produced by the spin-coating sol-gel method of the present invention have better control over composition and chemical uniformity than the existing magnetron sputtering method, lower cost and process difficulty, and can be prepared on a large scale.

[0034] Sixth, this invention utilizes Pb(Zr) doped with MO oxide. 0.52 Ti 0.48 Thin films prepared by spin coating of O3 sol-gel exhibit lower coercive field strength Ec and remanent polarization strength Pr, and show better fatigue resistance and lower energy consumption compared to thin films prepared by the same method. Attached Figure Description

[0035] Figure 1 This is a diagram of the core structure of the ultrathin stainless steel flexible substrate lead zirconate titanate-based piezoelectric-pyroelectric double-sided thin film sensor of the present invention. Figure 2 This invention provides a method for fabricating an ultrathin stainless steel flexible substrate lead zirconate titanate-based piezoelectric-pyroelectric double-sided thin-film sensor.

[0036] Process diagram;

[0037] Figure 3 Pb(Zr) prepared in Example 1 of this invention 0.52 Ti 0.48 Ferroelectric loop test spectrum of O3-xMO (40) multilayer composite thin film sample. Detailed Implementation

[0038] The embodiments and effects of the present invention will be further described in detail below with reference to the accompanying drawings.

[0039] Reference Figure 1 The present invention relates to an ultrathin stainless steel flexible substrate lead zirconate titanate-based piezoelectric-pyroelectric double-sided thin-film sensor, comprising a substrate, lead zirconate titanate (Pb(Zr)) and lead zirconate titanate (Pb(Zr)). 0.52 Ti 0.48 O3-xMO thin film layer, upper and lower electrode layers. Wherein:

[0040] The substrate is made of flexible stainless steel with a thickness of 2-100 μm, and is used as both the substrate and the lower electrode of the thin film.

[0041] The lead titanate (Pb(Zr) 0.52 Ti 0.48 A thin film layer (O3-xMO) with a thickness of 200nm-10um is applied to the upper and lower surfaces of a flexible stainless steel material. This double-sided flexible structure optimizes the stress distribution on both sides of the substrate, avoids excessive bending, and improves sensor stability. The metal oxide MO in the chemical formula is selected from one or more of copper oxide, bismuth oxide, lithium oxide, manganese oxide, and niobium oxide; x = 0.001 to 0.05 is the molar ratio of the doped oxide.

[0042] The upper electrode layer is selected from any one of silver, silver-palladium alloy, platinum, copper or nickel, and it is located on the surface of the upper and lower thin films.

[0043] Reference Figure 2 The present invention provides the following three embodiments:

[0044] Example 1: A sensor with a copper oxide molar ratio of 0.001 and a thin film thickness of 200 nm was fabricated on a 2 μm thick stainless steel substrate.

[0045] Step 1, Preparation of lead zirconate titanate-based (Pb(Zr)) 0.52 Ti 0.48 O3-xMO sol.

[0046] A Pb-containing solution was prepared by dissolving the raw material Pb(CH3COOH)2·3H2O in CH3COOH.

[0047] Zr(OC3H7)4 was dissolved in a mixed solution of CH3COOH and CH3COCH2COCH3 to obtain a Zr-containing solution;

[0048] Dissolve (Ti(OCH(CH3)2)4) in CH3COCH2COCH3 to obtain a Ti-containing solution;

[0049] The three solutions were mixed, and copper oxide with a molar ratio of 0.001 was added. The mixture was stirred at 50°C for 20 hours and then left to stand for 50 hours to obtain a Pb(Zr) solution with a concentration of 0.02 M. 0.52 Ti 0.48 O3-0.001CuO sol-gel.

[0050] Step 2: Spin-coating Pb(Zr) onto a 2µm stainless steel substrate. 0.52 Ti 0.48 O3-0.001CuO sol-gel.

[0051] The Pb(Zr) obtained in step 1 0.52 Ti 0.48 A wet film of O3-0.001CuO sol-gel was prepared by spin-coating on one side of the substrate at 3800 rpm for 8 seconds using a spin coater. After drying on a hot plate at 100°C for 60 minutes, Pb(Zr) was then spin-coated on the other side of the substrate at the same speed. 0.52 Ti 0.48 O3-0.001CuO sol-gel was also dried on a hot plate at 100℃ for 60 min.

[0052] Step 3: After pyrolyzing the sample obtained in Step 2 on a hot plate at 850°C for 270 min, it is then transferred to a hot plate at 800°C for annealing for 300 min to obtain a single-layer film on both the upper and lower surfaces of the substrate.

[0053] Step 4: Repeat steps (2) to (3) to obtain two layers of Pb(Zr) with a thickness of 200 nm on each side. 0.52 Ti 0.48 O3-0.001CuO composite film.

[0054] Step 5: Sputter Pt top electrodes with a thickness of 300 nm onto the upper and lower surfaces of the sample obtained in (4) using magnetron sputtering to complete the sensor fabrication.

[0055] Example 2: A sensor with a lithium oxide molar ratio of 0.05 and a thin film thickness of 5 μm was fabricated on a 100 μm thick stainless steel substrate.

[0056] Step 1: Preparation of lead zirconate titanate-based (Pb(Zr)) 0.52 Ti 0.48 O3-xMO sol.

[0057] Where MO is lithium oxide, and the molar ratio of the doped oxide is 0.05, the sol-gel is prepared by the following method;

[0058] A Pb-containing solution was prepared by dissolving the raw material Pb(CH3COOH)2·3H2O in CH3COOH.

[0059] Zr(OC3H7)4 was dissolved in a mixed solvent of CH3COOH and CH3COCH2COCH3 to obtain a Zr-containing solution;

[0060] Dissolve (Ti(OCH(CH3)2)4) in CH3COCH2COCH3 to obtain a Ti-containing solution;

[0061] The three solutions were mixed, lithium oxide was added, and the mixture was stirred at 200°C for 60 h and then left to stand for 90 h to obtain a 0.05 M Pb(Zr) solution. 0.52 Ti 0.48 O3-0.05Li2O sol-gel.

[0062] Step 2: Spin-coating Pb(Zr) onto a 100µm stainless steel substrate. 0.52 Ti 0.48 O3-0.05Li2O sol-gel.

[0063] The Pb(Zr) obtained in step one 0.52 Ti 0.48 A wet film of Pb(Zr) was prepared by spin-coating O3-0.05Li2O sol-gel onto one side of the substrate at 2400 rpm for 60 s using a spin coater. After drying on a hot plate at 300°C for 6 min, the film was then spin-coated onto the other side of the substrate using the same spin coater. 0.52 Ti 0.48 The O3-0.05Li2O sol-gel was also dried on a hot plate at 300℃ for 6 minutes.

[0064] Step 3: After pyrolyzing the sample obtained in Step 2 on a hot plate at 700℃ for 300 min, it is then transferred to a hot plate at 870℃ for annealing for 347 min to obtain a single-layer film on both the top and bottom surfaces of the substrate.

[0065] Step four: Repeat steps two and three to obtain 30 layers each on the front and back, with a thickness of 5 μm. 0.52 Ti 0.48 O3-0.05Li2O composite film.

[0066] Step 5: Use magnetron sputtering to sputter Au top electrodes with a thickness of 400 nm onto the upper and lower surfaces of the sample obtained in Step 4 to complete the sensor fabrication.

[0067] Example 3: A sensor with a manganese oxide molar ratio of 0.0035 and a thin film thickness of 9 μm was fabricated on a 50 μm thick stainless steel substrate.

[0068] Step A (1) Preparation of lead zirconate titanate-based (Pb(Zr)) 0.52 Ti 0.48 O3-xMO sol.

[0069] Where MO is manganese oxide, and the molar ratio of the doped oxide is 0.0035, the sol-gel is prepared by the following method;

[0070] A Pb-containing solution was prepared by dissolving the raw material Pb(CH3COOH)2·3H2O in CH3COOH.

[0071] Zr(OC3H7)4 was dissolved in a mixed solvent of CH3COOH and CH3COCH2COCH3 to obtain a Zr-containing solution;

[0072] Dissolve (Ti(OCH(CH3)2)4) in CH3COCH2COCH3 to obtain a Ti-containing solution;

[0073] The three solutions were mixed, manganese oxide was added, and the mixture was stirred at 250°C for 40 hours and then left to stand for 80 hours to obtain a Pb(Zr) solution with a concentration of 0.0035 M. 0.52 Ti 0.48 O3-0.05MnO sol-gel.

[0074] Step B: Spin-coating Pb(Zr) onto a 50µm stainless steel substrate. 0.52 Ti 0.48 O3-0.05MnO sol-gel.

[0075] The Pb(Zr) obtained in step A 0.52 Ti 0.48 A wet film of Pb(Zr) was prepared by spin-coating O3-0.05MnO sol-gel onto one side of the substrate at 6000 rpm for 55 s using a spin coater. After drying on a hot plate at 327°C for 30 min, the film was then spin-coated onto the other side of the substrate using the same spin coater. 0.52 Ti 0.48 O3-0.05MnO sol-gel was also dried on a hot plate at 327℃ for 30 min.

[0076] Step C: The sample obtained in Step B is pyrolyzed on a hot plate at 873°C for 300 min, and then transferred to a hot plate at 700°C for annealing for 315 min to obtain a single-layer film on both the top and bottom surfaces of the substrate.

[0077] Step D: Repeat steps B to C to obtain 15 layers on each side, with a thickness of 9 μm. 0.52 Ti0.48 O3-0.05MnO composite film.

[0078] Step E: Use magnetron sputtering to sputter Ag top electrodes with a thickness of 500 nm onto the upper and lower surfaces of the sample obtained in step D to complete the sensor fabrication.

[0079] The effectiveness of this invention can be further illustrated by the following test results.

[0080] I. Test Conditions

[0081] The voltage is set from 30kV to 90kV.

[0082] The testing instrument is a ferroelectric tester.

[0083] II. Test Content

[0084] Under the above conditions, the hysteresis loop of the sensor in Embodiment 3 of the present invention was tested under different voltages, and the results are as follows: Figure 3 .from Figure 3 As can be seen, this invention utilizes Pb(Zr) doped with MnO oxide. 0.52 Ti 0.48 The sensor film fabricated by spin-coating O3-0.05MnO sol-gel onto a flexible stainless steel substrate exhibits lower coercivity Ec and remanent polarization Pr, and shows better fatigue resistance and lower energy consumption compared to flexible sensor films fabricated by the same method.

[0085] The above descriptions are merely a few specific embodiments of the present invention and do not constitute any limitation on the present invention. Obviously, those skilled in the art, after understanding the content and principles of the present invention, may make various modifications and changes in form and detail without departing from the principles and structure of the present invention. For example, in addition to CuO, MnO, and Fe2O3 as described in the above embodiments, one or more of CaO, Al2O3, Sm2O3, and SiO2 can also be used; and in addition to silver, silver-palladium alloy, and copper as described in the above embodiments, platinum or nickel can also be used as the internal electrode material. However, these modifications and changes based on the concept of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. A dual-function, double-sided thin-film sensor based on lead zirconate titanate on an ultrathin stainless steel flexible substrate, comprising: Substrate, lead zirconate titanate (Pb(Zr 0.52 Ti 0.48 )O3-xMO) thin film layer, upper and lower electrode layers, characterized in that: The substrate is made of flexible stainless steel and is used as both the substrate for the thin film and the lower electrode layer. The thin film layer covers the upper and lower surfaces of the flexible stainless steel material to optimize the stress distribution on both sides of the substrate through a double-sided flexible structure, avoid excessive bending, and improve the stability of the sensor.

2. The sensor according to claim 1, characterized in that, The upper electrode layer is selected from any one of silver, silver-palladium alloy, platinum, copper, or nickel.

3. The sensor according to claim 1, characterized in that, The metal oxide MO in the chemical formula of lead zirconate titanate is selected from one or a combination of copper oxide, bismuth oxide, lithium oxide, manganese oxide, and niobium oxide; x = 0.001 to 0.05 is the molar ratio of the doped oxide.

4. The sensor according to claim 1, characterized in that, The flexible stainless steel material has a thickness of 2-100 μm.

5. The sensor according to claim 1, characterized in that, The thin film layer on the upper and lower surfaces of the stainless steel material has a thickness of 200nm-10um.

6. A method for fabricating an ultrathin stainless steel flexible substrate lead zirconate titanate-based piezoelectric-pyroelectric dual-functional double-sided thin-film sensor, characterized in that, Including the following: (1) Preparation of sol-gel: The raw material Pb(CH3COOH)2·3H2O was dissolved in CH3COOH to obtain a solution containing Pb; Zr(OC3H7)4 was dissolved in a mixed solvent of CH3COOH and CH3COCH2COCH3 to obtain a solution containing Zr. Dissolving (Ti(OCH(CH3)2)4) in CH3COCH2COCH3 yields a solution containing Ti; The three solutions are mixed, stirred at 50-250°C for 20-60h, and left to stand for 50-90h, to obtain a Pb(Zr 0.52 Ti 0.48 )O3-xMO sol-gel, where MO is a metal oxide, having a concentration of 0.01-0.8M. (2) Pb(Zr) 0.52 Ti 0.48 O3-xMO sol-gel was spin-coated onto one side of a clean, flexible stainless steel substrate and allowed to dry. Then, the sol-gel was spin-coated onto the other side and allowed to dry. (3) The sample obtained in step (2) is pyrolyzed to simultaneously produce a monolayer of Pb(Zr) on both sides of the substrate. 0.52 Ti 0.48 O3-xMO sol-gel film was prepared and then annealed. (4) Repeat steps (2) to (3) to obtain a bilayer Pb(Zr) with a total thickness of 200 nm to 10 μm. 0.52 Ti 0.48 O3-xMO(i) composite thin film; (5) A Pt / Au / Ag top electrode with a thickness of 300nm-500nm was sputtered on the upper and lower surfaces of the sample obtained in (4) using magnetron sputtering to complete the sensor fabrication.

7. The method according to claim 6, characterized in that, Step (2) Spin-coating the sol-gel, wherein the spin-coating speed is 3000-6000 rpm and the spin-coating time is 8-60 s; Step (2) Drying, wherein the drying temperature is 80-350℃ and the drying time is 2-60 min.

8. The method according to claim 6, characterized in that, In step (2), the spin-coated sol-gel sample is pyrolyzed at a temperature between 600-900℃ for 180-300 min.

9. The method according to claim 6, characterized in that, In step (2), the pyrolyzed sample is annealed at a temperature between 600-870℃ for a time of 220-347 min.

10. The method according to claim 6, characterized in that, Step (4) uses magnetron sputtering in Pb(Zr 0.52 Ti 0.48 The top and bottom surfaces of the O3-xMO (i) composite film were sputtered with Pt / Au / Ag top electrodes at a vacuum level of 4.0 × 10⁻⁶. -2 The sputtering current is 100-150mA and the sputtering thickness is 300-500nm.

Images