A kind of preparation method of the multiferroic complex phase ceramic of mosaic texture
Technical field
The present invention relates to a kind of preparation method of the multiferroic complex phase ceramic of mosaic texture.
Background technology
Multi-iron material refers to while at least having two kinds of performances in ferromagnetism, ferroelectricity or ferroelasticity and having coupling effect
Functional material.When using multi-iron material, you can to couple property using it, it is also possible to individually with certain property therein
Matter, therefore it applies quite varied, is related to the multiple fields such as microwave, storage, logical device.
Divide according to composition, multi-iron material can be divided into single phase multi-iron material and complex phase multi-iron material, single-phase many iron materials
Material poor performance, still can not put in practical application, and complex phase multi-iron material is taken seriously because its is magneto-electric coupled functional.
For complex phase multi-iron material (by ferroelectricity, ferromagnetism it is biphase it is compound as a example by) for, current two alternate composite squares
Formula has 0-3 (granule-block) type, 1-3 (cylinder-block) types and 2-2 (stratiform-stratiform) type, and different complex methods are produced not
Same magneto-electric coupled performance, but three kinds of complex methods cannot all solve electrical leakage problems:Ferromagnetic phase is present in the grain boundaries of ferroelectric phase,
Cause the leakage current that multiple orders of magnitude are higher by than single phase multi-iron material.
The content of the invention
The present invention is to solve the electric leakage that current complex phase multi-iron material is higher by multiple orders of magnitude than single phase multi-iron material
The technical problem of stream, and a kind of preparation method of the multiferroic complex phase ceramic of mosaic texture is provided.
A kind of preparation method of the multiferroic complex phase ceramic of mosaic texture of the present invention is carried out according to the following steps:
First, Sol A is prepared:Bismuth salt is uniformly mixed with acetic acid, is 100r/min~300r/min, heating in stir speed (S.S.)
Power is that 300W~500W and heating-up temperature are completely dissolved for heated and stirred under conditions of 70 DEG C~100 DEG C to bismuth salt, obtains bismuth
The acetic acid solution of salt, naturally cools to 40 DEG C~50 DEG C, adds solvent a, is then 100r/min~300r/ in stir speed (S.S.)
10min~15min is stirred under conditions of min, Sol A is obtained;
Bismuth salt described in step one is bismuth subnitrate or bismuth acetate;
The amount of the material of the bismuth salt described in step one is 1mmol with the volume ratio of acetic acid:(1.5mL~2.5mL);
Solvent a described in step one is ethylene glycol or ethylene glycol monomethyl ether;
Solvent a described in step one is 1 with the volume ratio of acetic acid:(1~5);
2nd, sol B is prepared:Slaine a is uniformly mixed with acetic acid, stir speed (S.S.) be 100r/min~300r/min and
Stir under conditions of room temperature to slaine a and be completely dissolved, obtain the acetic acid solution of slaine a, add solvent b, then in stirring
Speed is that 10min~15min is stirred under conditions of 100r/min~300r/min, obtains sol B;
Slaine a described in step one is sodium salt or potassium salt;
The amount of the material of the slaine a described in step one is 1mmol with the volume ratio of acetic acid:(0.4mL~0.8mL);
Solvent b described in step 2 is identical with the solvent a described in step one;
Solvent b described in step 2 is 1 with the volume ratio of acetic acid:(1~5);
3rd, solution C is prepared:Butyl titanate is uniformly mixed with solvent c, is 100r/min~300r/ in stir speed (S.S.)
Stir under conditions of min to solution clear, obtain solution c;
Solvent c described in step 3 is identical with the solvent a described in step one;
The amount of the material of the butyl titanate described in step 3 is 1mmol with the volume ratio of solvent c:(0.1mL~
0.4mL);
4th, according to chemical formula A0.5Bi0.5TiO3In each metallic element stoichiometric proportion by Sol A, sol B and solution
C uniformly mixes, and stirs 10min~15min with the stir speed (S.S.) of 100r/min~300r/min at room temperature, obtains colloidal sol D;Institute
The chemical formula A for stating0.5Bi0.5TiO3Middle A is sodium or potassium;
5th, colloidal sol E is prepared:Slaine b is uniformly mixed with ferric nitrate, acetic acid is subsequently adding, is 100r/ in stir speed (S.S.)
Min~300r/min, heating power be 100W~300W and heating-up temperature be under conditions of 50 DEG C~70 DEG C heated and stirred to gold
Category salt b is completely dissolved with ferric nitrate, naturally cools to 40 DEG C~50 DEG C, adds solvent d, stir speed (S.S.) for 100r/min~
10min~15min is stirred under conditions of 300r/min, colloidal sol E is obtained;
Slaine b described in step 5 is cobalt salt or nickel salt;
The metallic element in slaine b described in step 5 is 1 with the ratio of the amount of the material of ferrum in ferric nitrate:2;
The amount of the material of the slaine b described in step 5 is 1mmol with the volume ratio of acetic acid:(1mL~5mL);
Solvent d described in step 5 is identical with the solvent a described in step one;
Solvent d described in step 5 is 1 with the volume ratio of acetic acid:(2~5);
6th, mixed sols F is prepared:According to chemical formula aA0.5Bi0.5TiO3-bBFe2O4In each metallic element chemistry meter
Amount ratio is sufficiently mixed colloidal sol D and colloidal sol E, at room temperature with the stir speed (S.S.) of 100r/min~300r/min stir 10min~
15min, obtains mixed sols F;Described aA0.5Bi0.5TiO3-bBFe2O4In 0.5≤a≤0.95, a+b=1, A are sodium or potassium,
B is cobalt or nickel;
7th, dry:The mixed sols F obtained in step 6 is positioned in dustfree environment, is 25 DEG C~50 DEG C in temperature
Under conditions of be incubated 24h~168h, obtain mix xerogel;
8th, calcine:By the mixing xerogel obtained in step 7 with the heating rate of 1 DEG C/min~5 DEG C/min from room temperature
Be warming up to 100 DEG C~200 DEG C, temperature be 100 DEG C~200 DEG C under conditions of be incubated 30min~1h, then with 5 DEG C/min~
The heating rate of 15 DEG C/min is warming up to 350 DEG C~450 DEG C from 100 DEG C~200 DEG C, in the condition that temperature is 350 DEG C~450 DEG C
Lower insulation 1h~2h, then 600 DEG C~900 DEG C are warming up to from 350 DEG C~450 DEG C with the heating rate of 5 DEG C/min~15 DEG C/min,
1h~2h is incubated under conditions of temperature is for 600 DEG C~900 DEG C, then furnace cooling obtains ceramic powder;
9th, grind:The ceramic powder obtained in step 7 is placed in mortar and is ground, then cross 100 mesh~160 mesh
Sieve, collecting can cross the powder body of 100 mesh~160 mesh sieves;
Tenth, pelletize:Polyvinyl alcohol is uniformly mixed with deionized water, stir speed (S.S.) be 100r/min~300r/min,
Heating power is that 100W~300W and temperature are completely molten to polyvinyl alcohol to carry out heated and stirred under conditions of 50 DEG C~100 DEG C
Solution, obtains polyvinyl alcohol water solution;The powder body and polyvinyl alcohol that can cross 100 mesh~160 mesh sieves that obtain in step 9 is water-soluble
Liquid is added in mortar, is ground to mixture and is changed into uniformed powder from pasty substances;
The mass concentration of polyvinyl alcohol is 5% in described polyvinyl alcohol water solution;
Obtain in described polyvinyl alcohol water solution and step 9 can 100 mesh~160 mesh sieves of mistake powder body mass ratio
For 0.4:1;
11, tabletting:The uniformed powder obtained in step 10 is placed in mould, in the condition that pressure is 6MPa~8MPa
Lower pressurize 1min~3min, presses as block;
12, dumping:By the block obtained in step 11 with the heating rate of 0.5 DEG C/min~1.5 DEG C/min from room
Temperature is warming up to 500 DEG C~600 DEG C, and under conditions of temperature is for 500 DEG C~600 DEG C 30min~2h is incubated, and furnace cooling is to room
Temperature, obtains the ceramic green block without polyvinyl alcohol;
13, sinter:Under oxygen atmosphere, the powder body of 100 mesh~160 mesh sieves can be crossed by step with what is obtained in step 9
The embedding of the ceramic green block without polyvinyl alcohol obtained in 12, with 5 DEG C/min~10 DEG C/min's under oxygen atmosphere
Heating rate from room temperature to 1000 DEG C~1200 DEG C, under oxygen atmosphere and temperature be 1000 DEG C~1200 DEG C under conditions of
Insulation 30min~2h, then cools to room temperature with the furnace under oxygen atmosphere, obtains ferroelectric phase A0.5Bi0.5TiO3In inlay ferromagnetic
Phase BFe2O4Multiferroic complex phase ceramic block;A is sodium or potassium, and B is cobalt or nickel.
Advantages of the present invention:
First, in the multiferroic complex phase ceramic with mosaic texture prepared by the present invention, ferromagnetic phase is embedded in ferroelectric phase, compared with
Occur in less on ferroelectric phase crystal boundary or be not present on ferroelectric phase crystal boundary, its leakage current uses additive method system less than congruent
Standby ceramic block;
2nd, the sol-gel process process stabilizing that the present invention is used, the performance of product is homogeneous;
3rd, the sol-gel process that mid-early stage of the invention uses takes oven drying at low temperature, and the required energy is few, the calcining in later stage
With sintering process temperature less than additive method is used, energy waste can be effectively reduced;
The present invention can obtain the multiferroic complex phase ceramic with mosaic texture, and its leakage current is more less than 0-3,1-3,2-2 type
Ferrum complex phase ceramic.
Description of the drawings
Fig. 1 is to test a ferroelectric phase A for obtaining0.5Bi0.5TiO3In inlay ferromagnetic phase BFe2O4Multiferroic complex phase ceramic block
Body amplifies 7000 times of scanning electron microscope secondary electron image;
Fig. 2 is to test a ferroelectric phase A for obtaining0.5Bi0.5TiO3In inlay ferromagnetic phase BFe2O4Multiferroic complex phase ceramic block
Body amplifies 7000 times of scanning electron microscope backscattered electron image;
Fig. 3 is to test a ferroelectric phase A for obtaining0.5Bi0.5TiO3In inlay ferromagnetic phase BFe2O4Multiferroic complex phase ceramic block
The XRD figure of body;
Fig. 4 is the hysteresis curve figure of mosaic texture multiferroic composite ceramicses;
Fig. 5 is the ferroelectric hysteresis loop figure of mosaic texture multiferroic composite ceramicses.
Specific embodiment
Specific embodiment one:Present embodiment is a kind of preparation method of the multiferroic complex phase ceramic of mosaic texture, tool
Body is carried out according to the following steps:
First, Sol A is prepared:Bismuth salt is uniformly mixed with acetic acid, is 100r/min~300r/min, heating in stir speed (S.S.)
Power is that 300W~500W and heating-up temperature are completely dissolved for heated and stirred under conditions of 70 DEG C~100 DEG C to bismuth salt, obtains bismuth
The acetic acid solution of salt, naturally cools to 40 DEG C~50 DEG C, adds solvent a, is then 100r/min~300r/ in stir speed (S.S.)
10min~15min is stirred under conditions of min, Sol A is obtained;
Bismuth salt described in step one is bismuth subnitrate or bismuth acetate;
The amount of the material of the bismuth salt described in step one is 1mmol with the volume ratio of acetic acid:(1.5mL~2.5mL);
Solvent a described in step one is ethylene glycol or ethylene glycol monomethyl ether;
Solvent a described in step one is 1 with the volume ratio of acetic acid:(1~5);
2nd, sol B is prepared:Slaine a is uniformly mixed with acetic acid, stir speed (S.S.) be 100r/min~300r/min and
Stir under conditions of room temperature to slaine a and be completely dissolved, obtain the acetic acid solution of slaine a, add solvent b, then in stirring
Speed is that 10min~15min is stirred under conditions of 100r/min~300r/min, obtains sol B;
Slaine a described in step one is sodium salt or potassium salt;
The amount of the material of the slaine a described in step one is 1mmol with the volume ratio of acetic acid:(0.4mL~0.8mL);
Solvent b described in step 2 is identical with the solvent a described in step one;
Solvent b described in step 2 is 1 with the volume ratio of acetic acid:(1~5);
3rd, solution C is prepared:Butyl titanate is uniformly mixed with solvent c, is 100r/min~300r/ in stir speed (S.S.)
Stir under conditions of min to solution clear, obtain solution c;
Solvent c described in step 3 is identical with the solvent a described in step one;
The amount of the material of the butyl titanate described in step 3 is 1mmol with the volume ratio of solvent c:(0.1mL~
0.4mL);
4th, according to chemical formula A0.5Bi0.5TiO3In each metallic element stoichiometric proportion by Sol A, sol B and solution
C uniformly mixes, and stirs 10min~15min with the stir speed (S.S.) of 100r/min~300r/min at room temperature, obtains colloidal sol D;Institute
The chemical formula A for stating0.5Bi0.5TiO3Middle A is sodium or potassium;
5th, colloidal sol E is prepared:Slaine b is uniformly mixed with ferric nitrate, acetic acid is subsequently adding, is 100r/ in stir speed (S.S.)
Min~300r/min, heating power be 100W~300W and heating-up temperature be under conditions of 50 DEG C~70 DEG C heated and stirred to gold
Category salt b is completely dissolved with ferric nitrate, naturally cools to 40 DEG C~50 DEG C, adds solvent d, stir speed (S.S.) for 100r/min~
10min~15min is stirred under conditions of 300r/min, colloidal sol E is obtained;
Slaine b described in step 5 is cobalt salt or nickel salt;
The metallic element in slaine b described in step 5 is 1 with the ratio of the amount of the material of ferrum in ferric nitrate:2;
The amount of the material of the slaine b described in step 5 is 1mmol with the volume ratio of acetic acid:(1mL~5mL);
Solvent d described in step 5 is identical with the solvent a described in step one;
Solvent d described in step 5 is 1 with the volume ratio of acetic acid:(2~5);
6th, mixed sols F is prepared:According to chemical formula aA0.5Bi0.5TiO3-bBFe2O4In each metallic element chemistry meter
Amount ratio is sufficiently mixed colloidal sol D and colloidal sol E, at room temperature with the stir speed (S.S.) of 100r/min~300r/min stir 10min~
15min, obtains mixed sols F;Described aA0.5Bi0.5TiO3-bBFe2O4In 0.5≤a≤0.95, a+b=1, A are sodium or potassium,
B is cobalt or nickel;
7th, dry:The mixed sols F obtained in step 6 is positioned in dustfree environment, is 25 DEG C~50 DEG C in temperature
Under conditions of be incubated 24h~168h, obtain mix xerogel;
8th, calcine:By the mixing xerogel obtained in step 7 with the heating rate of 1 DEG C/min~5 DEG C/min from room temperature
Be warming up to 100 DEG C~200 DEG C, temperature be 100 DEG C~200 DEG C under conditions of be incubated 30min~1h, then with 5 DEG C/min~
The heating rate of 15 DEG C/min is warming up to 350 DEG C~450 DEG C from 100 DEG C~200 DEG C, in the condition that temperature is 350 DEG C~450 DEG C
Lower insulation 1h~2h, then 600 DEG C~900 DEG C are warming up to from 350 DEG C~450 DEG C with the heating rate of 5 DEG C/min~15 DEG C/min,
1h~2h is incubated under conditions of temperature is for 600 DEG C~900 DEG C, then furnace cooling obtains ceramic powder;
9th, grind:The ceramic powder obtained in step 7 is placed in mortar and is ground, then cross 100 mesh~160 mesh
Sieve, collecting can cross the powder body of 100 mesh~160 mesh sieves;
Tenth, pelletize:Polyvinyl alcohol is uniformly mixed with deionized water, stir speed (S.S.) be 100r/min~300r/min,
Heating power is that 100W~300W and temperature are completely molten to polyvinyl alcohol to carry out heated and stirred under conditions of 50 DEG C~100 DEG C
Solution, obtains polyvinyl alcohol water solution;The powder body and polyvinyl alcohol that can cross 100 mesh~160 mesh sieves that obtain in step 9 is water-soluble
Liquid is added in mortar, is ground to mixture and is changed into uniformed powder from pasty substances;
The mass concentration of polyvinyl alcohol is 5% in described polyvinyl alcohol water solution;
Obtain in described polyvinyl alcohol water solution and step 9 can 100 mesh~160 mesh sieves of mistake powder body mass ratio
For 0.4:1;
11, tabletting:The uniformed powder obtained in step 10 is placed in mould, in the condition that pressure is 6MPa~8MPa
Lower pressurize 1min~3min, presses as block;
12, dumping:By the block obtained in step 11 with the heating rate of 0.5 DEG C/min~1.5 DEG C/min from room
Temperature is warming up to 500 DEG C~600 DEG C, and under conditions of temperature is for 500 DEG C~600 DEG C 30min~2h is incubated, and furnace cooling is to room
Temperature, obtains the ceramic green block without polyvinyl alcohol;
13, sinter:Under oxygen atmosphere, the powder body of 100 mesh~160 mesh sieves can be crossed by step with what is obtained in step 9
The embedding of the ceramic green block without polyvinyl alcohol obtained in 12, with 5 DEG C/min~10 DEG C/min's under oxygen atmosphere
Heating rate from room temperature to 1000 DEG C~1200 DEG C, under oxygen atmosphere and temperature be 1000 DEG C~1200 DEG C under conditions of
Insulation 30min~2h, then cools to room temperature with the furnace under oxygen atmosphere, obtains ferroelectric phase A0.5Bi0.5TiO3In inlay ferromagnetic
Phase BFe2O4Multiferroic complex phase ceramic block;A is sodium or potassium, and B is cobalt or nickel.
Heating power 300W~500W used in present embodiment step one is higher than the 100W~300W's in step 5
Reason is that bismuth salt is more difficult to dissolving, and heat time heating time, the long bismuth salt that is easily caused was decomposed or other reactions.
By the mixing xerogel obtained in step 7 with the intensification of 1 DEG C/min~5 DEG C/min in present embodiment step 8
Speed is in order that Organic substance fully reacts simultaneously in this temperature 30min~1h from room temperature to 100 DEG C~200 DEG C
Making the gas in product fully volatilize prevents from gas from taking away powder body causing the loss of product and the change of stoichiometric proportion;Then with
The heating rate of 5 DEG C/min~15 DEG C/min rises to 350 DEG C~450 DEG C, and in this temperature 1h~2h be in order that
BFe2O4Crystallize first;Again 600 DEG C~900 DEG C are risen to the heating rate of 5 DEG C/min~15 DEG C/min, and in this temperature
The purpose of 1h~2h is so that A0.5Bi0.5TiO3Crystallization and by BFe2O4Inlay wherein.
Grinding purpose in present embodiment step 9 provides facility to refine and screening powder body for follow-up pelletize.
The effect of polyvinyl alcohol in present embodiment step 10 is binding agent, and carrying out mixed grinding using polyvinyl alcohol can be with
Obtain shape consistent, the tiny powder body with particle size distribution gradient.
The purpose sintered in present embodiment step 13 is so that ceramic green block occurs densification.
Specific embodiment two:This specific embodiment from unlike specific embodiment one:Sodium described in step one
Salt is sodium acetate or sodium nitrate.Other are identical with specific embodiment one.
Specific embodiment three:This specific embodiment from unlike specific embodiment one:Potassium described in step one
Salt is potassium acetate or potassium nitrate.Other are identical with specific embodiment one.
Specific embodiment four:This specific embodiment from unlike specific embodiment one:Described in step 5
Cobalt salt is cobalt nitrate or cobalt acetate.Other are identical with specific embodiment one.
Specific embodiment five:This specific embodiment from unlike specific embodiment one:Described in step 5
Nickel salt is nickel nitrate or nickel acetate.Other are identical with specific embodiment one.
The effect of the present invention is verified by tests below:
Test one:This test is a kind of preparation method of the multiferroic complex phase ceramic of mosaic texture, specifically by following step
Suddenly carry out:
First, Sol A is prepared:Bismuth salt is uniformly mixed with acetic acid, stir speed (S.S.) be 200r/min, heating power be 300W
It is completely dissolved to bismuth salt for heated and stirred under conditions of 100 DEG C with heating-up temperature, obtains the acetic acid solution of bismuth salt, naturally cools to
50 DEG C, solvent a is added, then stir 15min under conditions of stir speed (S.S.) is 200r/min, obtain Sol A;
Bismuth salt described in step one is bismuth subnitrate;
The amount of the material of the bismuth salt described in step one is 1mmol with the volume ratio of acetic acid:2mL;
Solvent a described in step one is ethylene glycol;
Solvent a described in step one is 1 with the volume ratio of acetic acid:2;
2nd, sol B is prepared:Slaine a is uniformly mixed with acetic acid, in the condition that stir speed (S.S.) is 200r/min and room temperature
Under stir to slaine a and be completely dissolved, obtain the acetic acid solution of slaine a, add solvent b, be then 200r/ in stir speed (S.S.)
15min is stirred under conditions of min, sol B is obtained;
Slaine a described in step one is sodium salt;
The amount of the material of the slaine a described in step one is 1mmol with the volume ratio of acetic acid:0.5mL;
Solvent b described in step 2 is identical with the solvent a described in step one;
Solvent b described in step 2 is 1 with the volume ratio of acetic acid:1;
3rd, solution C is prepared:Butyl titanate is uniformly mixed with solvent c, under conditions of stir speed (S.S.) is 200r/min
Stir to solution clear, obtain solution c;
Solvent c described in step 3 is identical with the solvent a described in step one;
The amount of the material of the butyl titanate described in step 3 is 1mmol with the volume ratio of solvent c:0.3mL;
4th, according to chemical formula A0.5Bi0.5TiO3In each metallic element stoichiometric proportion by Sol A, sol B and solution
C uniformly mixes, and stirs 15min with the stir speed (S.S.) of 200r/min at room temperature, obtains colloidal sol D;Described chemical formula
A0.5Bi0.5TiO3Middle A is sodium;
5th, colloidal sol E is prepared:Slaine b is uniformly mixed with ferric nitrate, acetic acid is subsequently adding, is 200r/ in stir speed (S.S.)
Min, heating power are that 100W and heating-up temperature are completely dissolved for heated and stirred under conditions of 50 DEG C to slaine b and ferric nitrate,
50 DEG C are naturally cooled to, solvent d is added, under conditions of stir speed (S.S.) is 200r/min 15min is stirred, obtain colloidal sol E;
Slaine b described in step 5 is cobalt salt;
The metallic element in slaine b described in step 5 is 1 with the ratio of the amount of the material of ferrum in ferric nitrate:2;
The amount of the material of the slaine b described in step 5 is 1mmol with the volume ratio of acetic acid:1mL;
Solvent d described in step 5 is identical with the solvent a described in step one;
Solvent d described in step 5 is 1 with the volume ratio of acetic acid:2;
6th, mixed sols F is prepared:According to chemical formula aA0.5Bi0.5TiO3-bBFe2O4In each metallic element chemistry meter
Amount ratio is sufficiently mixed colloidal sol D and colloidal sol E, stirs 15min with the stir speed (S.S.) of 200r/min at room temperature, obtains mixed sols
F;Described aA0.5Bi0.5TiO3-bBFe2O4Middle a=0.95, b=0.05, A are sodium, and B is cobalt;
7th, dry:The mixed sols F obtained in step 6 is positioned in dustfree environment, in the condition that temperature is 40 DEG C
Lower insulation 96h, obtains mixing xerogel;
8th, calcine:By the mixing xerogel obtained in step 7 with the heating rate of 1 DEG C/min from room temperature to 150
DEG C, 1h is incubated under conditions of temperature is for 150 DEG C, then 350 DEG C are warming up to from 150 DEG C with the heating rate of 5 DEG C/min, in temperature
Spend to be incubated 1h under conditions of 350 DEG C, then 700 DEG C are warming up to from 350 DEG C with the heating rate of 5 DEG C/min, be 700 DEG C in temperature
Under conditions of be incubated 1h, then furnace cooling obtains ceramic powder;
9th, grind:The ceramic powder obtained in step 7 is placed in mortar and is ground, then cross 160 mesh sieves, collected
The powder body of 160 mesh sieves can be crossed;
Tenth, pelletize:Polyvinyl alcohol is uniformly mixed with deionized water, is that 200r/min, heating power are in stir speed (S.S.)
100W and temperature are completely dissolved to carry out heated and stirred under conditions of 50 DEG C to polyvinyl alcohol, obtain polyvinyl alcohol water solution;Will
The powder body and polyvinyl alcohol water solution that can cross 160 mesh sieves obtained in step 9 is added in mortar, is ground to mixture by paste
Shape material is changed into uniformed powder;
The mass concentration of polyvinyl alcohol is 5% in described polyvinyl alcohol water solution;
The mass ratio of the powder body that can cross 160 mesh sieves obtained in described polyvinyl alcohol water solution and step 9 is 0.4:1;
11, tabletting:The uniformed powder obtained in step 10 is placed in mould, the pressurize under conditions of pressure is 6MPa
1min, presses as block;
12, dumping:By the block obtained in step 11 with the heating rate of 1 DEG C/min from room temperature to 500 DEG C,
1h is incubated under conditions of temperature is for 500 DEG C, furnace cooling to room temperature obtains the ceramic green block without polyvinyl alcohol;
13, sinter:Under oxygen atmosphere, the powder body of 160 mesh sieves can be crossed by step 12 with what is obtained in step 9
The embedding of the ceramic green block without polyvinyl alcohol for obtaining, with the heating rate of 5 DEG C/min from room temperature liter under oxygen atmosphere
Temperature is then cold with stove under oxygen atmosphere with temperature to be incubated 50min under conditions of 1150 DEG C under oxygen atmosphere to 1150 DEG C
But to room temperature, ferroelectric phase A is obtained0.5Bi0.5TiO3In inlay ferromagnetic phase BFe2O4Multiferroic complex phase ceramic block;A is sodium, and B is
Cobalt.
Sodium salt described in step one is sodium acetate;Cobalt salt described in step 5 is cobalt nitrate.
Fig. 1 is to test a ferroelectric phase A for obtaining0.5Bi0.5TiO3In inlay ferromagnetic phase BFe2O4Multiferroic complex phase ceramic block
Body amplifies 7000 times of scanning electron microscope secondary electron image, and Fig. 2 is to test a ferroelectric phase A for obtaining0.5Bi0.5TiO3-
In inlay ferromagnetic phase BFe2O4Multiferroic complex phase ceramic block amplify 7000 times of scanning electron microscope backscattered electron figure
Picture, Fig. 1 and Fig. 2 is shown the same area.
Fig. 1 is demonstrated by the grain morphology of mosaic texture multiferroic composite ceramicses, has two kinds of crystal grain, i.e. four directions shape and isometry
Shape.
Fig. 2 is demonstrated by the component distributing of mosaic texture multiferroic composite ceramicses, has the crystal grain of two kinds of colors, i.e., light color is brilliant
Grain and dark crystal grain, CoFe in two kinds of crystal grain2O4Content it is different.By taking light crystal grain as an example, ferromagnetic phase CoFe2O4It is embedded in
Ferroelectric phase Na0.5Bi0.5TiO3In, dark-shaded can be seen in crystal grain core, and have the CoFe of dark color2O4Crystal grain is inlayed
Wherein, these dark CoFe2O4A diameter of 500nm~2 μm of crystal grain.
Fig. 3 is to test a ferroelectric phase A for obtaining0.5Bi0.5TiO3In inlay ferromagnetic phase BFe2O4Multiferroic complex phase ceramic block
The XRD figure of body, ▼ is Na0.5Bi0.5TiO3, ● it is CoFe2O4, contrasted using standard card (card number 46-0001,03-0864)
Gains Na mutually really for needed for is found afterwards0.5Bi0.5TiO3And CoFe2O4, and the intensity of diffraction maximum also complies with biphase content
Ratio.
Test one is obtained ferroelectric phase A using vibrating specimen magnetometer (VSM)0.5Bi0.5TiO3In inlay ferromagnetic phase
BFe2O4Multiferroic complex phase ceramic block carry out magnetism testing, as shown in figure 4, Fig. 4 is mosaic texture multiferroic composite ceramicses
Hysteresis curve figure, wherein saturation magnetization be 18.8emu/g, according to CoFe2O4Shared actual volume is converted into
46.3emu/g, the magnetic of mosaic texture multiferroic composite ceramicses is good.
Test one is obtained ferroelectric phase A using ferroelectricity test system0.5Bi0.5TiO3In inlay ferromagnetic phase BFe2O4It is many
Ferrum complex phase ceramic block carries out ferroelectric properties test, as shown in figure 5, Fig. 5 is the electric hysteresis of mosaic texture multiferroic composite ceramicses
Loop line figure, the electric field intensity of curve 1 is 100KV/cm, and the electric field intensity of curve 2 is 120KV/cm, and the electric field intensity of curve 3 is
140KV/cm, the electric field intensity of curve 4 is 160KV/cm, and wherein remanent polarization is 38.2 (μ C/cm2), mosaic texture is more
The ferroelectric hysteresis loop rectangular degree of ferrum composite ceramicses is high, and leakage current is little, and actual measurement leakage current is 10-6(Amps/cm2) order of magnitude.