CN105023692A - Multiferroic liquid and preparation method thereof - Google Patents

Abstract

The invention discloses a multiferroic liquid and a preparation method thereof. The multiferroic liquid of the present invention is prepared through the following steps: first, uniformly mix the base liquid and the surfactant to mix the mixed liquid; then add ferroelectric nanoparticles and magnetic nanoparticles to the mixed liquid for shaking and put it into a sealed container Put it on a shaker and shake it for more than half an hour to obtain a stable suspension in which the nanoparticles are uniformly dispersed in the mixed liquid, that is, a multiferroic liquid. The multiferroic liquid of the present invention not only has magnetism, ferroelectricity but also fluidity, and is very sensitive to magnetic field and electric field; it has smaller coercive force than solid ferroelectric material multiferroic liquid, and the particles are stable under electric field or magnetic field. It is easy to rotate; it also has the properties that solid multiferroic materials do not have, such as magneto-optic effect and refraction effect. The invention proposes a multiferroic liquid and a preparation method for the first time, opening up a new direction for the research of multiferroic materials.

Description

A kind of multiferroic liquid and preparation method thereof

technical field

The invention belongs to the field of multiferroic materials, and in particular relates to a multiferroic liquid and a preparation method thereof.

Background technique

In 1994, Schmid in Switzerland clearly proposed the concept of multiferroic materials. Multiferroic materials (mutliferroic) refer to the basic properties of two or more types of iron in the same phase of the material. These basic properties of iron include iron Electricity (antiferroelectricity), ferromagnetism (antiferromagnetism, ferrimagnetism) and ferroelasticity. This kind of material has both spontaneous polarization order and spin order at a certain temperature. It is the magnetoelectric coupling effect caused by their simultaneous existence that makes multiferroics have some special physical properties and triggers several new , Significant physical phenomena, such as: generating electric polarization or inducing ferroelectric phase transition under the action of a magnetic field; generating a magnetic field or inducing ferromagnetic phase transition under the action of an electric field; Constant mutation, multiferroic materials have become a hotspot in current international research.

Ferroelectric materials have excellent properties such as ferroelectricity, dielectricity, pyroelectricity, electro-optic properties, acousto-optic properties, and nonlinear optics. They are used in ferroelectric memories, infrared detectors, sensors, surface acoustic waves, integrated optoelectronic devices, There are very important applications in solid-state devices such as capacitors, which also greatly promotes the research and development of ferroelectric materials and ferroelectric physics. Ferroelectric random access memory based on ferroelectric materials has great application prospects due to its non-volatility and fast read speed. Ferroelectric materials and their applications have become one of the most popular research topics in the fields of condensed matter physics and solid-state electronics.

At present, there are not many materials with ferroelectric order and magnetic order at the same time. The typical ones are bismuth ferrite (BiFeO ₃ , referred to as BFO), bismuth manganate (BiMnO ₃ , referred to as BMO), and Roch salt (NaKC ₄ H ₄ O ₆ .4H ₂ O), BaFe ₁₂ O ₁₉ , etc. Even so, the multiferroic materials studied so far are all in the solid state, including multiferroic ceramics, multiferroic thin films, and multiferroic single crystals. Solid multiferroic materials have the following disadvantages: 1. The coercive force of solid multiferroic materials is relatively large. When magnetic or electric fields are used to regulate magnetism or ferroelectricity, the required magnetic or electric fields are relatively large; 2. .When studying the magnetoelectric coupling effect, it is found that the effect is relatively weak and the change is not obvious; 3. If the electric field is too large, the multiferroic material will be easily damaged, resulting in material waste; 4. Once the multiferroic material is formed, its structure cannot be changed .

At present, there are not many single-phase materials with ferroelectric order and magnetic order at the same time, and these materials are either not magnetic enough, or the ferroelectricity is relatively weak, or the Curie temperature is relatively low (only at low temperatures). magnetism and ferroelectricity). Liquid multiferroic materials have not been reported yet, and there is no concept of "multiferroic liquid" in the world. This is because, when the multiferroic material is in a liquefied state, the temperature is generally higher than its ferroelectric or ferromagnetic Curie temperature, and the multiferroic material has lost ferroelectricity and/or ferromagnetism at this time. (or ferrimagnetic, antiferromagnetic). Therefore, we put forward the concept of "multiferroic liquid" for the first time, and gave its preparation method.

Contents of the invention

In order to solve the shortcomings of the above-mentioned solid multiferroic materials, the present invention provides a multiferroic liquid and a preparation method thereof.

The present invention is realized through the following technical solutions:

A multiferroic liquid, comprising magnetic nanoparticles, ferroelectric nanoparticles, a base liquid, and a surfactant, wherein the base liquid and the surfactant are uniformly mixed into a mixed liquid, the magnetic nanoparticles, The ferroelectric nanoparticles are uniformly dispersed in the mixed liquid to form a stable suspension.

Further, the particle diameter of the magnetic nanoparticles is ≦20nm.

Further, the particle size of the ferroelectric nanoparticles is ≦20 nm.

Further, the base liquid is water, an organic liquid or an organic aqueous solution.

Further, the base liquid is silicone oil, dodecylbenzene or polybutene oil.

Further, the surfactant is at least one of oleic acid, aminododecane, fluetheric acid, lauric acid, and phenylundecanoic acid.

The method for preparing any of the above-mentioned multiferroic liquids comprises the following steps:

Preparation of dry magnetic nanoparticles, dry ferroelectric nanoparticles, base fluid and surfactant;

Mix the base liquid and surfactant evenly into a mixed liquid, add magnetic nanoparticles and ferroelectric nanoparticles into the mixed liquid, shake to avoid the aggregation and precipitation of the nanoparticles, then put the mixed liquid into a sealed container and Shake on a shaker until a stable suspension is formed to obtain a multiferroic liquid.

Further, in order to uniformly disperse the nanoparticles in the mixed liquid to form a stable suspension, the shaking time of the shaker is longer than half an hour.

Beneficial effects of the present invention:

1. For solid multiferroic materials, the coercive force is relatively large. When a magnetic or electric field is used to regulate the magnetism or ferroelectricity, the required magnetic or electric field is relatively large. In multiferroic liquids, since the nanoparticles are suspended in the liquid, the nanoparticles are affected by Brownian motion, and the resistance of the liquid to the movement of the nanoparticles is much smaller than that of the solid. Under the action of an electric field (magnetic field), nanoparticles can rotate in the liquid, and their magnetic moment or polarization direction can be changed accordingly; however, in solid multiferroic materials, the crystal grains obviously cannot rotate, and the resistance is very large.

2. For solid multiferroic materials, when studying the magnetoelectric coupling effect, it is found that the magnetoelectric coupling effect is relatively weak. However, magnetic nanoparticles and ferroelectric nanoparticles are suspended in the multiferroic liquid state. When an electric field is applied, the ferroelectric nanoparticles will rotate, and the electric dipole moment (electric moment) will turn to the direction of the electric field and form Chain-like, and the electric field required to turn the electric moment in the liquid is much smaller than that of solid multiferroic materials. In the process of rotation or other motion, the ferroelectric nanoparticles will interact with the magnetic nanoparticles, thereby affecting the position, direction, and shape of the magnetic nanoparticles, thereby realizing the regulation of the magnetic properties of the multiferroic liquid by the electric field. Conversely, when a magnetic field is applied, the magnetic moments of the magnetic nanoparticles will easily rotate, move and form chains in the direction of the magnetic field. During rotation or other motions, magnetic nanoparticles will affect the position, direction, and shape of ferroelectric nanoparticles, thereby regulating the ferroelectricity of multiferroic liquids. Therefore, as long as a small electric field or magnetic field is applied, the direction of the electric moment (polarization direction) or the direction of the magnetic moment can be rotated, and the movement of the ferroelectric nanoparticles will act on the magnetic nanoparticles, whereas the movement of the magnetic nanoparticles under the magnetic field It will also affect the ferroelectric nanoparticles, thereby realizing and improving the magnetoelectric coupling effect of the multiferroic liquid.

3. For solid multiferroic materials, if the applied electric field is too large, the multiferroic materials are easily broken down by the electric field and damaged, and this breakdown is permanent and cannot be recovered, resulting in waste of multiferroic materials. For multiferroic liquids, after a certain point is broken by an electric field breakdown, you only need to remove the electric (magnetic) field, shake the multiferroic liquid again, and then apply the electric (magnetic) field again, and the multiferroic liquid can recover again. use. Moreover, multiferroic liquids only need a small electric field to change their polarization direction, so they are not easy to be broken down.

4. For solid multiferroic materials, once the structure is formed, it cannot be changed. As for the multiferroic liquid, due to the fluidity of the liquid, its internal structure is changeable. After applying an electric (magnetic) field to the multiferroic liquid, the length and thickness of the nanochains can be easily changed. Moreover, the electric (magnetic) field can be applied as required, and the electric (magnetic) field will not be given when not in use, and the electric (magnetic) field electric (magnetic) field will be applied when needed, and the electric (magnetic) field can be removed after use. magnetic field. Moreover, the structure of nanochains can be controlled at will by changing parameters such as the magnitude, direction, and gradient of the electric (magnetic) field. For example, if a photovoltaic cell is made of a solid multiferroic material, the thickness of the film layer is constant, and the distance between the electrodes and the area of the electrodes are constant; if it is a nanowire, then the length, thickness, and distance of the nanowire are both is constant. Using a multiferroic liquid, the length, thickness, and distance of the nanochains can be changed by changing the magnitude and direction of the electric (magnetic) field and other factors.

5. Multiferroic liquid has the properties of magneto-optical effect and refraction effect which are not found in solid multiferroic materials.

6. Under the action of electric field or magnetic field, the orientation of electric domains in solid multiferroic materials can only be along certain orientations close to the direction of electric field, not necessarily along the direction of electric field. For multiferroic liquids, due to Nanoparticles can rotate freely in the liquid, so the orientation of their electrical domains can be completely along the direction of the electric field.

Since multiferroic liquids are both multiferroic and fluid, they have many unique ferroelectric, hydrodynamic, optical and acoustic properties. When a multiferroic liquid is placed in a uniform electric field of a certain intensity, when a beam of polarized light passes through, there will be differences in the absorption of the electric vector of the polarized light parallel to the direction of the external electric field and perpendicular to the direction of the external electric field, so it is optically anisotropic. A series of electro-optic effects such as Faraday effect and birefringence effect will be produced. It is estimated that multiferroic liquids will have conductivity dispersion and ferroelectric viscosity in alternating field. Likewise, the magnetism of multiferroic liquids can be controlled by an electric field, which in turn can be altered by applying a magnetic field.

In a word, the present invention proposes the concept of multiferroic liquid for the first time and discloses the preparation method of multiferroic liquid, which has opened up a new research direction for the research of multiferroic materials, thereby broadening the research scope of multiferroic materials. The different properties of multiferroic liquids are thoroughly studied and utilized, so that multiferroic materials can be more fully applied. The multiferroic liquid of the present invention is that magnetic nanoparticles and ferroelectric nanoparticles are evenly dispersed in the base liquid to form a stable suspension, and the multiferroic liquid has magnetism, ferroelectricity and fluidity at the same time. Theoretically, A brand-new multiferroic material with both ferroelectricity and magnetism is provided, and the application range of the multiferroic liquid of the invention will be wider than that of the solid multiferroic material.

Description of drawings

Fig. 1 is the multiferroic liquid schematic diagram of the present invention;

Fig. 2 is that the multiferroic liquid of the present invention forms chains along the direction of the magnetic field in the multiferroic liquid under a magnetic field;

Fig. 3 is that the multiferroic liquid of the present invention forms chains in the multiferroic liquid along the direction of the electric field in the multiferroic liquid;

Fig. 4 is that the multiferroic liquid of the present invention forms a chain along the direction of the electric field and magnetic field in the multiferroic liquid under the electric field and magnetic field applied in the same direction;

Fig. 5 is the variation situation of its light transmittance of multiferroic liquid of the present invention under different magnetic fields;

Fig. 6 shows the variation of the light transmittance of the multiferroic liquid of the present invention under different electric fields.

Detailed ways

The present invention will be further described below in conjunction with drawings and embodiments.

A multiferroic liquid, comprising magnetic nanoparticles, ferroelectric nanoparticles, a base liquid, and a surfactant, wherein the base liquid and the surfactant are uniformly mixed into a mixed liquid, the magnetic nanoparticles, The ferroelectric nanoparticles are uniformly dispersed in the mixed liquid to form a stable suspension. The ferroelectric nanoparticles are barium titanate (BTO), lead zirconate titanate (PZT) or ferric oxide (Fe ₃ O ₄ ), and the magnetic nanoparticles are cobalt ferrite (CoFe ₂ O ₄ , CFO for short) or γ-Fe ₂ O ₃ (those skilled in the art should know that other ferroelectric materials and magnetic materials can also be selected as required). The nanoparticles are ferroelectric (or magnetic) nanoparticles or nanowires. The particle size of the magnetic nanoparticles is≦20nm. The particle size of the ferroelectric nanoparticles is≦20nm. The smaller the particle size of the nanoparticles, the better, and the smaller the particle size, the less likely the nanoparticles are to precipitate due to Coulomb movement. Conversely, the larger the particle size, the easier it is to precipitate due to the action of gravity, and the suspension cannot be formed. If the particle size is large, a base liquid with a high density must be selected, and the buoyancy is used to offset the gravity, so the selection of the base liquid is relatively harsh, and there are fewer base liquids to choose from. The base liquid is water, organic liquid or organic aqueous solution. In order to be able to characterize the multiferroicity of the multiferroic liquid, it is necessary to apply an electric field or a magnetic field to the multiferroic liquid, so that the ferroelectric nanoparticles or magnetic nanoparticles in the liquid are polarized. Therefore, the base fluid should choose a liquid with poor conductivity, such as grease close to insulation. In addition, it should have other properties: high breakdown strength, small dielectric loss tangent, high insulation resistivity, relative permittivity Small; followed by excellent physical and chemical properties. Such as high vaporization temperature, high flash point, flame retardant or non-combustible as far as possible; low freezing point, suitable viscosity and viscosity-temperature characteristics; high thermal conductivity, large specific heat capacity; good thermal stability, oxidation resistance; gas absorption under the action of electric field Small; it has better compatibility with the solid material it comes in contact with; low toxicity and easy biodegradation. It also requires wide sources and low prices. Silicone oil, dodecylbenzene, polybutene oil, etc. for use at high temperatures are preferable. Choose a surfactant oleic acid, aminododecane, fluoroether acid, lauric acid, or phenylundecanoic acid that matches the dielectric properties of the base fluid. The selected surfactant is capable of both coating the nanoparticles and soluble in the selected base fluid. Moreover, the total volume fraction of ferroelectric nanoparticles and magnetic nanoparticles is preferably not more than 20%. The larger the volume fraction, the easier it is to agglomerate, and finally settle down, unable to form a stable suspension. If the volume fraction is too large, the requirements for surfactants and base fluids will be higher, and the range of options will be narrower. Except for special needs, the overall integral score will be more stable within 5%, and it will not be easy to reunite and precipitate.

Preparation of BTO-CFO multiferroic liquid:

Step 1: Preparation of ferroelectric BTO nanoparticles by sol-gel method

1) Preparation of barium precursor solution: add an appropriate amount of glacial acetic acid to barium acetate, heat and dissolve in a constant temperature water bath at 80°C, transfer it to a volumetric flask after cooling, and use a burette to drop ethylene glycol ether to constant volume. Ba precursor. 2) Preparation of titanium precursor solution: Add glacial acetic acid and ethylene glycol ether as a mixed solvent to tetrabutyl titanate, transfer it to a volumetric flask after dissolution, and use a burette to drop ethylene glycol ether to constant volume to obtain Ti Precursor. Add the Ti precursor solution dropwise to the Ba precursor solution, add an appropriate amount of acetylacetone after the dropwise addition to adjust the viscosity of the sol, and mix well to obtain a pure barium titanate sol after 24 hours. To prepare a sol doped with barium titanate, it is only necessary to add an appropriate amount of La precursor, Nd precursor or Co precursor at the same time, and after 24 hours of aging, the sol doped with barium titanate can be obtained. If necessary, an appropriate amount of ethanolamine can also be added to control the viscosity of the sol. Then the obtained solution was baked on a heating platform, and then put into a box furnace for sintering at a sintering temperature of 900° C. for 2 hours. After the obtained product is thoroughly ground, BTO nanoparticles are obtained.

Step 2: Preparation of CoFe ₂ O ₄ (CFO) Magnetic Nanoparticles by Co-precipitation Method

FeCl ₃ 6H ₂ O (0.04mol, 100mL) was mixed with Co(NO ₃ ) ₂ 6H ₂ O (0.02mol, 100mL), NaOH (0.35mol, 500mL) was added, and the mixed solution was heated to boiling with After rapid stirring and boiling for 1 min, the natural precipitate was removed; after sufficient precipitation, the precipitate was washed with 1mol/L H(NO) ₃ solution until the pH value was 7, and then the cleaned product was dehydrated and dried with acetone Finally, the required CFO magnetic nanoparticles are obtained.

Step 3: Preparation of BTO-CFO Multiferroic Liquid

Silicone oil has the characteristics of high and low temperature resistance, good chemical stability, low vapor pressure, and viscosity is not affected by temperature. It is an ideal carrier liquid for multiferroic liquids. However, the hydrophobic and oleophobic properties of silicone oil make the surfactant that uniformly disperses ferroelectric BTO and magnetic CFO particles in it must have lipophilic properties and be able to coat magnetic particles and ferroelectric particles, otherwise agglomeration will easily occur , subsidence, etc. Oleic acid was selected as the surfactant.

A BTO-CFO multiferroic liquid with a volume fraction of magnetic nanoparticles of 5%, a volume fraction of ferroelectric nanoparticles of 5%, and a total volume of 100 ml was prepared.

method one:

The required volume of BTO and CFO nanoparticles is 5ml, and its density is about 6g/cm ³ , then the mass of BTO and CFO is required to be 30g; the concentration of oleic acid is 2%, then 2ml of oleic acid needs to be measured; silicone oil The volume is 100-10-2=88ml.

First, weigh 30g of BTO nanoparticles (volume about 5cm ³ ) and 30g of CFO nanoparticles (volume about 5cm ³ ), and add BTO nanoparticles and CFO nanoparticles to the uniformly mixed mixed liquid of 2ml oleic acid and 88ml silicone oil , shake to avoid particle agglomeration and precipitation, then seal the container containing the mixed liquid (to prevent shaking out of the container when shaking) and place it on a shaker for shaking for about 1 hour. That is, a BTO-CFO multiferroic liquid with a volume fraction of ferroelectric nanoparticles of 5%, a volume fraction of magnetic nanoparticles of 5%, and a total volume of 100 ml was obtained.

Method Two:

The BTO ferroelectric liquid mother solution that the volume fraction of BTO ferroelectric nanoparticles is 5% and the total volume is 100ml is prepared:

The required volume of BTO nanoparticles is 5ml, and its density is about 6g/cm ³ , then the mass of BTO is required to be 30g; the concentration of oleic acid is 2%, then 2ml of oleic acid needs to be measured; the volume of silicone oil is 100-5 -2 = 93ml.

First, weigh 30g of BTO nanoparticles (volume about 5cm ³ ), add BTO nanoparticles to the uniformly mixed mixed liquid of 2ml oleic acid and 93ml silicone oil, shake to avoid particle agglomeration and precipitation, and then put the mixed liquid The container was sealed (to prevent shaking out of the container when shaken) and placed on a shaker for approximately 1 hour on a shaker. That is, a BTO ferroelectric liquid mother solution with a volume fraction of ferroelectric nanoparticles of 5% and a total volume of 100 ml was obtained.

The CFO magnetic liquid mother liquor whose volume fraction of CFO magnetic nanoparticles is 5% and whose total volume is 100ml is prepared:

The required volume of CFO nanoparticles is 5ml, and its density is about 6g/cm ³ , so the mass of CFO needs to be 30g; the concentration of oleic acid is 2%, and 2ml of oleic acid needs to be measured; the volume of silicone oil is 100-5 -2 = 93ml.

First, weigh 30g of CFO nanoparticles (volume about 5cm ³ ), then add CFO nanoparticles into the uniformly mixed mixed liquid of 2ml oleic acid and 93ml silicone oil, shake it to avoid particle agglomeration and precipitation, and then put the mixed liquid The container was sealed (to prevent shaking out of the container when shaking) and placed on a shaker for shaking for about 1 hour. That is, a CFO magnetic liquid mother liquor with a volume fraction of 5% magnetic nanoparticles and a volume of 100 ml was obtained.

Take 50ml of BTO ferroelectric liquid mother liquor and 50ml of CFO magnetic liquid mother liquor respectively and mix them, seal and shake on a shaker for 1 hour, and obtain ferroelectric nanoparticles with a volume fraction of 5%, magnetic nanoparticles BTO-CFO multiferroic liquid with a volume fraction of 5% and a total volume of 100 ml.

The base liquid and surfactant used to configure the BFO multiferroic liquid mother liquid and the CFO magnetic liquid mother liquid are the same to prevent precipitation after the two are mixed.

Method 2 can also first prepare ferroelectric liquid mother liquid and magnetic liquid mother liquid with different volume fractions, and then measure corresponding volumes of ferroelectric liquid mother liquid and magnetic liquid mother liquid according to configuration requirements, and then add a certain amount of base liquid or base liquid The mixed liquid of liquid and surfactant is shaken on a shaker until a stable suspension is formed, thereby obtaining a multiferroic liquid.

In summary, we can configure multiferroic liquids with different volume percentages of ferroelectric nanoparticles and magnetic nanoparticles according to the needs of research. To study the shape and movement of ferroelectric nanoparticles controlled by magnetic field, the proportion of magnetic nanoparticles should be relatively large, preferably 30%-80% of the total nanoparticle volume, less than 30%. Although movement and shape have certain influence on ferroelectric nanoparticles, they do not play a key role; if more than 80%, although magnetic nanoparticles can obviously affect ferroelectric nanoparticles, the Since the ratio is too small, the performance change will not be great. Conversely, if it is necessary to study the relationship between the movement, properties, or structure of magnetic nanoparticles and other properties, then in order to regulate the structure of ferroelectric nanoparticles and magnetic nanoparticles through electric fields, ferroelectric nanoparticle The particle volume is preferably 30%-80% of the total particle volume.

As shown in Figure 1, the black circles in Figure 1 represent magnetic nanoparticles, which can be CFO, Fe ₃ O ₄ and so on. The gray circles represent ferroelectric nanoparticles, which can be BTO, PZT, etc. The gray area represents the base fluid, which can be water, acids, oils, hydrocarbons, etc.

As shown in Figure 2, after a magnetic field is applied in the vertical direction, the magnetic nanoparticles are arranged in an orderly manner along the direction of the magnetic field, forming a chain, which can control other properties, such as light transmission. In addition, ferroelectric nanoparticles will also move under the action of magnetic nanochains, indicating that not only magnetic properties can be regulated by magnetic fields, but also electrical properties can be regulated by magnetic fields.

As shown in Figure 3, after applying an electric field along the vertical direction, the ferroelectric nanoparticles are arranged in an orderly manner along the direction of the electric field, forming a chain, which can control other properties, such as light transmission. In addition, magnetic nanoparticles will also move under the action of ferroelectric nanochains, indicating that not only ferroelectricity can be regulated by electric field, but also magnetic properties can be regulated by electric field. It has certain application value in sensors, sealing devices and the like.

As shown in Figure 4, after an electric field and a magnetic field are applied simultaneously in the vertical direction, the ferroelectric nanoparticles are arranged in an orderly manner along the direction of the electric field, forming a chain, and at the same time, the magnetic nanoparticles are also released under the action of the magnetic field. Form a chain, as shown in Figure 4. In this way, other properties, such as light transmission, ferroelectricity, magnetism, fluidity, etc., can be regulated through electric and magnetic fields, which has certain application value.

As shown in Figure 5, the multiferroic liquid with a total volume fraction of ferroelectric nanoparticles and magnetic nanoparticles of 10%, and the multiferroic liquid with a volume fraction of ferroelectric nanoparticles and magnetic nanoparticles of 5% were added Transmittance of light after a magnetic field as a function of time. It can be found that the magnetic field has a certain regulation effect on the light transmittance. As shown in Figure 6, the multiferroic liquid with a total volume fraction of ferroelectric nanoparticles and magnetic nanoparticles of 10%, and the multiferroic liquid with a volume fraction of ferroelectric nanoparticles and magnetic nanoparticles of 5% were added Transmittance of light after an electric field as a function of time. The electric field in a is 200kV/m, and the electric field strength in b is 500kV/m. It can be found that the electric field has a certain regulation effect on the light transmittance.

Claims (8)

1. a multiferroic liquid, it is characterized in that: comprise the nano particle of magnetic, ferroelectric nano particle, base fluid, surfactant, described base fluid and described surfactant are uniformly mixed into mixing material, and the nano particle of described magnetic, ferroelectric nano particle are dispersed in described mixing material and form stable suspension.

2. multiferroic liquid according to claim 1, is characterized in that: the Li Jing≤20nm of the nano particle of described magnetic.

3. multiferroic liquid according to claim 1, is characterized in that: the Li Jing≤20nm of described ferroelectric nano particle.

4. multiferroic liquid according to claim 1, is characterized in that: described base fluid is water, organic liquid or aqueous organopolysiloxane.

5. multiferroic liquid according to claim 1, is characterized in that: described base fluid is silicone oil, detergent alkylate or Polybutene oil.

6. multiferroic liquid according to claim 1, is characterized in that: described surfactant is oleic acid, aminododecane, fluorine ether acid, laurate, phenyl undecanoic acid at least one.

7. prepare the method for the arbitrary described multiferroic liquid of claim 1-6, it is characterized in that: comprise the following steps:

Prepare dry magnetic nanoparticle, dry ferroelectricity nano particle, base fluid and surfactant;

Be mixing material base fluid and surfactant Homogeneous phase mixing;

The nano particle of magnetic, ferroelectric nano particle are joined in mixing material, rock and avoid nanoparticle agglomerates, precipitation, again mixing material to be loaded in the container of sealing and to be placed on shaking table and to shake, until form stable suspension, namely obtaining multiferroic liquid.

8. the method preparing multiferroic liquid according to claim 7, is characterized in that: the shaking table shake time is greater than half an hour.