Preparation method of magnetoelectric composite ceramic with embedded structure

Abstract

The invention discloses a preparation method of magnetoelectric composite ceramic with an embedded structure, and relates to a preparation method of magnetoelectric composite ceramic. The invention aims to solve the problem of low magnetoelectric interface coupling efficiency. The magnetoelectric composite ceramic with the embedded structure is formed by compounding a ferroelectric phase PbZr52Ti48O3 and a ferromagnetic phase CoFe2O4. The preparation method comprises the following steps: 1, preparing sol A; 2, preparing sol B; 3, preparing sol C; 4, aging the sol; 5, calcining; 6, granulating; 7, forming; 8, discharging glue; 9, isostatic pressing; and 10, sintering. The magnetoelectric composite ceramic with the embedded structure is used for detecting the magnetic field size and the magnetic field frequency. The prepared magnetoelectric composite ceramic with the embedded structure is low in resonant frequency and high in magnetoelectric response intensity at the resonant frequency, and the magnetic field intensity (the sensitivity is 10 <-7 > T) and the magnetic field frequency (the sensitivity is 10 Hz) can be accurately measured.

Description

Technical Field

[0001] The present invention relates to a preparation method of a magnetoelectric composite ceramic. Background Art

[0002] In recent decades, the industrial level has developed rapidly, and the demand for magnetic field detection devices has been continuously high. Widely used magnetic field detection devices include Hall sensors, magnetoresistive sensors, and magnetoelectric sensors. Among them, magnetoelectric sensors have attracted extensive attention due to their simple assembly, simple operation, and high detection sensitivity, and play an important role in the field of electronics industry. At present, magnetoelectric composite material systems are mainly divided into three coupling types: 0-3, 2-2, and 1-3. The 2-2 type has the most prominent composite effect and is the most widely used composite material at present. However, for the 2-2 type magnetoelectric composite, cracks or cracking are likely to occur due to different thermal expansion coefficients during conventional or hot-press integrated sintering. For non-integrated sintered 2-2 type magnetoelectric composites, most are bonded with epoxy resin glue. At room temperature, due to the stiffness mismatch of the magnetic-glue-electric interface layer, epoxy resin will absorb part of the mechanical stress, reducing the magnetoelectric coupling between them. And as the use time of the magnetoelectric material increases, the temperature of the epoxy resin layer rises rapidly, and the phenomenon of colloid melting will occur, causing the colloid to lose its bonding ability. The preparation of 1-3 type magnetoelectric composite materials is very difficult, and the 1-3 type materials are usually manufactured by the cutting and filling process. And during the subsequent polarization process, the high electrical conductivity of the magnetic phase will cause a large leakage current in the composite material during polarization, resulting in material breakdown. These problems are ultimately due to the loose interface connection between the two-phase materials, leading to problems such as easy cracking, easy stress loss, and easy breakdown, which limit the improvement of the magnetoelectric coupling performance of the materials. Summary of the Invention

[0003] The purpose of the present invention is to provide a preparation method of a magnetoelectric composite ceramic with an inlaid structure to solve the problem of low magnetoelectric interface coupling efficiency.

[0004] A preparation method of a magnetoelectric composite ceramic with an inlaid structure, the magnetoelectric composite ceramic with an inlaid structure prepared by the preparation method is composed of a ferroelectric phase PbZr 52 Ti 48 O3 and a ferromagnetic phase CoFe2O4, and the preparation method is specifically completed according to the following steps:

[0005] I. Preparation of Sol A:

[0006] ①. Add iron nitrate, cobalt nitrate, and lead acetate into anhydrous acetic acid, seal it, and then stir and heat until iron nitrate, cobalt nitrate, and lead acetate are completely dissolved in anhydrous acetic acid to obtain Solution I;

[0007] ②. Cool Solution I to room temperature, then add ethylene glycol and stir to obtain Sol A;

[0008] II. Preparation of Sol B:

[0009] ①. Add zirconium propoxide to tetrabutyl titanate and stir to obtain Solution II;

[0010] ②. Add ethylene glycol to Solution II and stir to obtain Sol B;

[0011] III. Preparation of Sol C;

[0012] Drop Sol B into Sol A and stir to obtain Sol C;

[0013] IV. Aging of Sol:

[0014] Age Sol C in an oven for a period of time to obtain a crystalline xerogel;

[0015] V. Calcination:

[0016] Grind the crystalline xerogel, and then place it in a box furnace for calcination. The calcination procedure is as follows:

[0017] ①. Heat from room temperature to 250°C - 350°C;

[0018] ②. Keep the temperature at 250°C - 350°C for 1h - 2h;

[0019] ③. Heat from 250°C - 350°C to 700°C - 800°C;

[0020] ④. Keep the temperature at 700°C - 800°C for 1h - 2h;

[0021] ⑤. Cool down to room temperature to obtain the calcined powder;

[0022] VI. Granulation:

[0023] Add the calcined powder to a 5% polyvinyl alcohol solution, then grind and screen to obtain the granulated and screened powder;

[0024] VII. Molding:

[0025] Load the granulated and screened powder into a mold, then apply a pressure of 600 MPa - 700 MPa and keep it warm for a period of time to obtain the formed green body;

[0026] VIII. Debinding:

[0027] Place the formed green body in a muffle furnace, heat it to 500°C - 600°C, and keep it warm for a period of time to obtain the debound body;

[0028] IX. Isostatic Pressing:

[0029] Apply a pressure of 200 MPa to the debound green body in a cold isostatic press and hold the pressure for a period of time to obtain a cold isostatically pressed green body;

[0030] X. Sintering:

[0031] Place the cold isostatically pressed green body in a muffle furnace, heat it to 1100 °C - 1125 °C, and hold the temperature for a period of time to obtain a magnetoelectric composite ceramic with an inlaid structure.

[0032] Advantages of the present invention:

[0033] I. The sol - gel process used in the present invention is simple, with low operation difficulty and a short dry gel cycle;

[0034] II. The magnetoelectric composite ceramic with an inlaid structure prepared by the present invention has some ferromagnetic phases inlaid in the ferroelectric phase;

[0035] III. The magnetoelectric composite ceramic with an inlaid structure prepared by the present invention has a uniform distribution of magnetic phases, and the interface between the embedded magnetic phase and the piezoelectric phase is closely connected. The stress and strain generated by the magnetic phase (piezoelectric phase) can be effectively transmitted to the piezoelectric phase (magnetic phase). It can have a good magnetoelectric coupling coefficient under the condition of a relatively low proportion of magnetic phases, improving the magnetoelectric coupling efficiency. The magnetoelectric coupling performance is improved by 30%, thereby improving the performance of magnetic field detection;

[0036] IV. The magnetoelectric composite ceramic with an inlaid structure prepared by the present invention has a low resonance frequency and a large magnetoelectric response intensity at the resonance frequency, and can accurately measure the magnetic field strength (sensitivity is 10 -7 T) and the magnetic field frequency (sensitivity is 10 Hz). Description of the Drawings

[0037] Figure 1 Is a physical diagram of sol C prepared in Example 1;

[0038] Figure 2 Is a structural diagram of the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1;

[0039] Figure 3 Is a schematic diagram of the device for magnetoelectric testing of the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1;

[0040] Figure 4 Is a magnetoelectric coupling diagram of the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1;

[0041] Figure 5 Is an effect diagram of the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1 for detecting the magnetic field frequency;

[0042] Figure 6Effect diagram of detecting the magnetic field strength by the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1;

[0043] Figure 7 Test chart of the magnetoelectric coupling coefficient of the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1 and the non-inlaid ceramic prepared in Comparative Example 1. Specific implementation manners

[0044] Specific implementation manner 1: A preparation method of a magnetoelectric composite ceramic with an inlaid structure. The magnetoelectric composite ceramic with an inlaid structure prepared by this preparation method is composed of a ferroelectric phase PbZr 52 Ti 48 O3 and a ferromagnetic phase CoFe2O4. The specific preparation method is completed according to the following steps:

[0045] I. Preparation of sol A:

[0046] ①. Add iron nitrate, cobalt nitrate and lead acetate into anhydrous acetic acid, seal it, and then stir and heat until iron nitrate, cobalt nitrate and lead acetate are completely dissolved in anhydrous acetic acid to obtain solution I;

[0047] ②. Cool solution I to room temperature, then add ethylene glycol and stir to obtain sol A;

[0048] II. Preparation of sol B:

[0049] ①. Add zirconium propoxide into tetrabutyl titanate and stir to obtain solution II;

[0050] ②. Add ethylene glycol to solution II and stir to obtain sol B;

[0051] III. Preparation of sol C;

[0052] Drop sol B into sol A and stir to obtain sol C;

[0053] IV. Aging of the sol:

[0054] Age sol C in an oven for a period of time to obtain a crystalline xerogel;

[0055] V. Calcination:

[0056] Grind the crystalline xerogel, and then put it into a box furnace for calcination. The calcination procedure is as follows:

[0057] ①. Heat from room temperature to 250°C - 350°C;

[0058] ②. Keep the temperature at 250°C - 350°C for 1h - 2h;

[0059] ③. Heat from 250°C - 350°C to 700°C - 800°C;

[0060] ④. Keep it at 700 °C to 800 °C for 1 h to 2 h;

[0061] ⑤. Cool it down to room temperature to obtain the calcined powder;

[0062] VI. Granulation:

[0063] Add the calcined powder to a polyvinyl alcohol solution with a mass fraction of 5%, then grind and sieve it to obtain the granulated and sieved powder;

[0064] VII. Molding:

[0065] Load the granulated and sieved powder into a mold, then apply a pressure of 600 MPa to 700 MPa and keep it warm for a period of time to obtain the formed green body;

[0066] VIII. Debinding:

[0067] Put the formed green body into a muffle furnace, heat it up to 500 °C to 600 °C, and keep it warm for a period of time to obtain the debound body;

[0068] IX. Isostatic pressing:

[0069] Apply a pressure of 200 MPa to the debound body in a cold isostatic press and keep the pressure for a period of time to obtain the cold isostatically pressed body;

[0070] X. Sintering:

[0071] Place the cold isostatically pressed body in a muffle furnace, heat it up to 1100 °C to 1125 °C, and keep it warm for a period of time to obtain the magnetoelectric composite ceramic with an inlaid structure.

[0072] Specific Embodiment 2: The difference between this embodiment and Specific Embodiment 1 is that: in step ① of step one, the molar ratio of ferric nitrate, cobalt nitrate and lead acetate is 2:1:(1 - 19); in step ① of step one, the molar ratio of ferric nitrate to the volume of acetic acid is 5 mol:2 L; in step ① of step one, the heating temperature is 80 °C to 100 °C. Other steps are the same as those in Specific Embodiment 1.

[0073] Specific Embodiment 3: The difference between this embodiment and one of Specific Embodiment 1 or 2 is that: in step ② of step one, the volume ratio of ethylene glycol to the anhydrous acetic acid in step ① is about (2 - 3):1; in step ② of step one, the stirring time is 10 min to 20 min. Other steps are the same as those in Specific Embodiment 1 or 2.

[0074] Specific Embodiment Four: The differences between this embodiment and any one of Embodiments One to Three are as follows: In step 2①, the molar ratio of zirconium propoxide to tetrabutyl titanate is 13:12; the stirring time in step 2① is 10 min to 20 min; in step 2②, the volume ratio of ethylene glycol to the ethylene glycol in step 1② is 1:1; the stirring time in step 2② is 10 min to 20 min. Other steps are the same as those in Embodiments One to Three.

[0075] Specific Embodiment Five: The differences between this embodiment and any one of Embodiments One to Four are as follows: In step 3, the volume ratio of Sol A to Sol B is 1:1; the stirring time in step 3 is 20 min to 40 min. Other steps are the same as those in Embodiments One to Four.

[0076] Specific Embodiment Six: The differences between this embodiment and any one of Embodiments One to Five are as follows: In step 4, the temperature of the oven is 60°C to 70°C; the aging time in step 4 is 5 to 7 days. Other steps are the same as those in Embodiments One to Five.

[0077] Specific Embodiment Seven: The differences between this embodiment and any one of Embodiments One to Six are as follows: In step 5①, the heating rate is 0.5°C / min to 2°C / min; in step 5③, the heating rate is 5°C / min to 10°C / min; in step 5⑤, the cooling rate is 5°C / min. Other steps are the same as those in Embodiments One to Six.

[0078] Specific Embodiment Eight: The differences between this embodiment and any one of Embodiments One to Seven are as follows: In step 6, the mass of polyvinyl alcohol in the 5% polyvinyl alcohol solution by mass is 2% of the mass of the calcined powder; the sieving in step 6 is through a 160-mesh sieve. Other steps are the same as those in Embodiments One to Seven.

[0079] Specific Embodiment Nine: The differences between this embodiment and any one of Embodiments One to Eight are as follows: In step 7, the heat preservation time is 3 min to 5 min; the thickness of the green body in step 7 is 1 mm; in step 8, the heat preservation time is 2 h to 3 h; the heating rate in step 8 is 1°C / min. Other steps are the same as those in Embodiments One to Eight.

[0080] Specific Embodiment Ten: The differences between this embodiment and any one of Embodiments One to Nine are as follows: In step 9, the pressure holding time is 3 min to 5 min; in step 10, the heating rate is 5°C / min to 10°C / min; in step 10, the heat preservation time is 2 h to 3 h. Other steps are the same as those in Embodiments One to Nine.

[0081] The beneficial effects of the present invention are verified by the following embodiments:

[0082] Embodiment 1: A preparation method of a magnetoelectric composite ceramic with an inlaid structure, wherein the magnetoelectric composite ceramic with an inlaid structure is composed of a ferroelectric phase PbZr 52 Ti 48 O3 (PZT) and a ferromagnetic phase CoFe2O4 (CFO), where Pb is lead, Zr is zirconium, Ti is titanium, O is oxygen, Co is cobalt, and Fe is iron; the preparation method is specifically completed according to the following steps:

[0083] I. Preparation of sol A:

[0084] ①. Add iron nitrate, cobalt nitrate, and lead acetate to acetic acid, seal, and then stir and heat until iron nitrate, cobalt nitrate, and lead acetate are completely dissolved in acetic acid to obtain solution I;

[0085] In step I①, the molar ratio of iron nitrate, cobalt nitrate, and lead acetate is 2:1:1;

[0086] In step I①, the molar ratio of iron nitrate to the volume of acetic acid is 5 mol:2 L;

[0087] In step I①, the heating temperature is 90 °C;

[0088] ②. Cool solution I to room temperature, then add ethylene glycol and stir for 15 min to obtain sol A;

[0089] In step I②, the volume ratio of ethylene glycol to acetic acid in step I① is about 2.5:1;

[0090] II. Preparation of sol B:

[0091] ①. Add zirconium propoxide to tetrabutyl titanate and stir for 15 min to obtain solution II;

[0092] In step II①, the molar ratio of zirconium propoxide to tetrabutyl titanate is 13:12;

[0093] ②. Add ethylene glycol to solution II and stir for 15 min to obtain sol B;

[0094] In step II②, the volume ratio of ethylene glycol to ethylene glycol in step I② is 1:1;

[0095] III. Preparation of sol C;

[0096] Drop sol B into sol A and stir for 30 min to obtain sol C;

[0097] In step III, the volume ratio of sol A to sol B is 1:1;

[0098] IV. Sol-gel aging:

[0099] The sol C is aged in an oven at 60 °C for a period of time to obtain a crystalline xerogel;

[0100] The aging time described in step IV is 7 days;

[0101] V. Calcination:

[0102] The crystalline xerogel is ground and then placed in a box furnace for calcination. The calcination procedure is as follows:

[0103] ①. Heat up from room temperature to 300 °C;

[0104] ②. Keep the temperature at 300 °C for 1 h;

[0105] ③. Heat up from 300 °C to 700 °C;

[0106] ④. Keep the temperature at 700 °C for 1 h;

[0107] ⑤. Cool down to room temperature to obtain the calcined powder;

[0108] The heating rate described in step V① is 1 °C / min;

[0109] The heating rate described in step V③ is 5 °C / min;

[0110] The cooling rate described in step V⑤ is 5 °C / min;

[0111] VI. Granulation:

[0112] The calcined powder is added to a 5% polyvinyl alcohol solution by mass, and then ground and sieved to obtain the granulated and sieved powder;

[0113] The mass of polyvinyl alcohol in the 5% polyvinyl alcohol solution by mass described in step VI is 2% of the mass of the calcined powder;

[0114] The sieving described in step VI is through a 160-mesh sieve;

[0115] VII. Molding:

[0116] The granulated and sieved powder is loaded into a mold, and then a pressure of 600 MPa is applied and kept warm for 4 min to obtain a formed green body with a thickness of 1 mm;

[0117] VIII. Debinding:

[0118] The formed green body is placed in a muffle furnace, heated up to 550 °C, and kept warm for a period of time to obtain the debound body;

[0119] The heat preservation time described in Step 8 is 2 h;

[0120] The heating rate described in Step 8 is 1 °C / min;

[0121] IX. Isostatic pressing:

[0122] Apply a pressure of 200 MPa to the debound green body in a cold isostatic press and hold the pressure for 3 min to obtain a cold isostatically pressed green body;

[0123] X. Sintering:

[0124] Place the cold isostatically pressed green body in a muffle furnace, heat it to 1100 °C, and keep it warm for 2 h to obtain a magnetoelectric composite ceramic with an inlaid structure;

[0125] The heating rate described in Step X is 5 °C / min.

[0126] Comparative Example 1: The difference between the preparation method of the non-inlaid ceramic and that of Example 1 lies in:

[0127] V. Calcination:

[0128] Grind the crystalline xerogel and then put it into a box furnace for calcination. The calcination procedure is as follows:

[0129] I. Heat from room temperature to 200 °C at a heating rate of 1 °C / min;

[0130] II. Heat from 200 °C to 700 °C at a heating rate of 5 °C / min;

[0131] III. Keep it warm at 700 °C for 1 h;

[0132] IV. Cool down to room temperature to obtain the calcined powder. Other steps and parameters are the same as those in Example 1.

[0133] Figure 1 is a physical picture of Sol C prepared in Example 1;

[0134] From Figure 1 it can be seen that Sol C prepared in Example 1 is clear and transparent without any precipitation.

[0135] Figure 2 is a structural diagram of the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1;

[0136] From Figure 2 it can be seen that the magnetic phase is evenly distributed, and some magnetic phases are embedded in the piezoelectric phase (the black is the magnetic phase, and the white is the piezoelectric phase).

[0137] Figure 3 is a schematic diagram of the device for magnetoelectric testing of the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1;

[0138] Figure 3 is an existing device, and only its test fixture is improved. From Figure 3 it can be seen that: The Helmholtz Coils provide a DC bias magnetic field of 700 Oe; the Coils provide an AC magnetic field with a frequency varying range of 100 - 100 kHz and a magnetic field magnitude of (0 - 5.625 Oe); the Composite Material is placed at the center of the AC coil; the Lock-in Amplifer processes the voltage signal collected on the sample; the signal processed by the lock-in amplifier is displayed on the PC.

[0139] Figure 4 is the magnetoelectric coupling diagram of the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1;

[0140] During the test, the sample is subjected to a frequency sweep test, and it responds most strongly to the magnetic field at the resonance frequency of the material, which is 51 kHz.

[0141] Place the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1 in a small AC solenoid (coil(AC)), give the Heomholtz Coil (DC) a DC bias magnetic field, and by changing the frequency of the AC coil, the Figure 5 data can be obtained;

[0142] Figure 5 is the effect diagram of detecting the magnetic field frequency of the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1;

[0143] From Figure 5 it can be seen that: The response of the magnetoelectric coupling coefficient to the magnetic field change is also the strongest at 51 kHz. The signals with magnetic field frequencies of 50.95k - 51 kHz are tested in detail. For every 10 Hz change, the signal magnitude changes significantly, indicating that the material responds significantly to the magnetic field frequency change near the resonance frequency, and the sensitivity is less than or equal to 10 Hz.

[0144] Place the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1 in a small AC solenoid (coil(AC)), give the Heomholtz Coil (DC) a DC bias magnetic field, change the voltage magnitude of the AC coil, and the corresponding magnetic field inside the coil will change accordingly, then the Figure 6 data can be obtained;

[0145] Figure 6 is the effect diagram of detecting the magnetic field magnitude of the magnetoelectric composite ceramic with an inlaid structure prepared in Example 1;

[0146] FromFigure 6 It can be known that at the resonance frequency of 51 kHz, the lowest detectable magnetic field magnitude is 45 μT, and the magnetic field sensitivity is 22 μT.

[0147] Figure 7 Test chart of the magnetoelectric coupling coefficient of the mosaic - structured magnetoelectric composite ceramics prepared in Example 1 and the non - mosaic ceramics prepared in Comparative Example 1.

[0148] From Figure 7 It can be known that for the ceramic material prepared by the traditional one - step calcination method in Comparative Example 1, under the condition of a bias magnetic field of 1.3 kOe, the maximum magnetoelectric coupling coefficient is 60 μV / (cmOe), while for the ceramic material prepared by the "mosaic - structured magnetoelectric composite ceramic preparation method" mentioned in Example 1, under the condition of a bias magnetic field of 1.3 kOe, the maximum magnetoelectric coupling coefficient is 78 μV / (cmOe), and the magnetoelectric coupling performance is improved by 30%.

Claims

1. A method for preparing a magnetoelectric composite ceramic with a mosaic structure, characterized in that The magnetoelectric composite ceramic with mosaic structure prepared by the preparation method is composed of ferroelectric phase PbZr 52 Ti 48 O3 and ferromagnetic phase CoFe2O4 are composited, and the preparation method is specifically completed in the following steps:

1. Preparation of Sol A: ①, add ferric nitrate, cobalt nitrate and lead acetate into anhydrous acetic acid, seal, stir and heat until ferric nitrate, cobalt nitrate and lead acetate are completely dissolved in anhydrous acetic acid to obtain solution I; ②, Cool solution I to room temperature, then add ethylene glycol and stir to obtain sol A; 2. Preparation of Sol B: ①, adding zirconium n-propoxide to tetrabutyl titanate, stirring, to obtain solution II; ②, add ethylene glycol to solution II, stir, and obtain sol B; 3. Preparation of Sol C; Sol B was added dropwise to Sol A, and the mixture was stirred to obtain Sol C; 4. Sol aging: The sol C was aged in an oven for a period of time to obtain a crystalline xerogel; 5. Calcination: The crystalline dry gel is ground and then placed in a box furnace for calcination. The calcination procedure is as follows: ①. Raise the temperature from room temperature to 250℃~350℃; ②, keep warm at 250℃~350℃ for 1h~2h; ③. Raise the temperature from 250℃~350℃ to 700℃~800℃; ④. Keep warm at 700℃~800℃ for 1h~2h; ⑤. Cool down to room temperature to obtain calcined powder; 6. Granulation: The calcined powder is added into a polyvinyl alcohol solution with a mass fraction of 5%, and then ground and sieved to obtain a granulated and sieved powder; 7. Molding: The granulated and sieved powder is loaded into a mold, and then a pressure of 600MPa to 700MPa is applied and kept warm for a period of time to obtain a green blank after molding; 8. Debinding: The formed green body is placed in a muffle furnace, heated to 500°C to 600°C, and kept warm for a period of time to obtain a green body after debinding; 9. Isostatic pressing: Apply a pressure of 200 MPa to the debinded green body in a cold isostatic press and maintain the pressure for a period of time to obtain a green body after cold isostatic pressing; 10. Sintering: The green body after cold isostatic pressing is placed in a muffle furnace, heated to 1100° C. to 1125° C., and kept warm for a period of time to obtain a magnetoelectric composite ceramic with a mosaic structure.

2. The method for preparing a magnetoelectric composite ceramic with a mosaic structure according to claim 1, characterized in that The molar ratio of ferric nitrate, cobalt nitrate and lead acetate described in step 1① is 2:1:(1-19); the volume ratio of the amount of ferric nitrate described in step 1① to acetic acid is 5 mol:2L; the heating temperature described in step 1① is 80°C-100°C.

3. The method for preparing a magnetoelectric composite ceramic with a mosaic structure according to claim 1, characterized in that The volume ratio of the ethylene glycol described in step 1② to the anhydrous acetic acid described in step 1① is approximately (2-3):1; the stirring time described in step 1② is 10min-20min.

4. The method for preparing a magnetoelectric composite ceramic with a mosaic structure according to claim 1, characterized in that The molar ratio of zirconium n-propoxide to tetrabutyl titanate described in step 2① is 13:12; the stirring time described in step 2① is 10min to 20min; the volume ratio of ethylene glycol described in step 2② to ethylene glycol described in step 1② is 1:1; the stirring time described in step 2② is 10min to 20min.

5. The method for preparing a magnetoelectric composite ceramic with a mosaic structure according to claim 1, characterized in that The volume ratio of Sol A to Sol B in step 3 is 1:1; the stirring time in step 3 is 20 min to 40 min.

6. The method for preparing a magnetoelectric composite ceramic with a mosaic structure according to claim 1, characterized in that The temperature of the oven described in step 4 is 60° C. to 70° C.; the aging time described in step 4 is 5 to 7 days.

7. The method for preparing a magnetoelectric composite ceramic with a mosaic structure according to claim 1, characterized in that The heating rate described in step 5① is 0.5℃ / min~2℃ / min; the heating rate described in step 5③ is 5℃ / min~10℃ / min; the cooling rate described in step 5⑤ is 5℃ / min.

8. The method for preparing a magnetoelectric composite ceramic with a mosaic structure according to claim 1, characterized in that The mass of polyvinyl alcohol in the 5% polyvinyl alcohol solution described in step 6 is 2% of the mass of the calcined powder; the sieving described in step 6 is sieving through a 160-mesh sieve.

9. The method for preparing a magnetoelectric composite ceramic with a mosaic structure according to claim 1, characterized in that The insulation time in step seven is 3 minutes to 5 minutes; the thickness of the blank in step seven is 1 mm; the insulation time in step eight is 2 hours to 3 hours; the heating rate in step eight is 1°C / min.

10. The method for preparing a magnetoelectric composite ceramic with a mosaic structure according to claim 1, characterized in that The holding time in step nine is 3 minutes to 5 minutes; the heating rate in step ten is 5°C / min to 10°C / min; the holding time in step ten is 2 hours to 3 hours.

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