CN106587975A - Zinc ferrite material and preparation method thereof - Google Patents

Abstract

The invention discloses a zinc ferrite material and a preparation method thereof, belonging to the field of magnetic materials, wherein the preparation method includes the following steps: ingredients: raw materials include iron acetylacetonate, zinc acetylacetonate, surfactant and solvent; The solvent is dibenzyl ether or 1-octadecene or oleylamine; wherein the molar ratio of zinc acetylacetonate and iron acetylacetonate is 0.1 to 0.8, and the molar ratio of the total amount of iron acetylacetonate and zinc acetylacetonate to the surfactant is 0.01 to 0.85, the amount of solvent can fully dissolve iron acetylacetonate and zinc acetylacetonate; put the raw materials in a protective gas environment, and mix them at room temperature; then the product particles obtained after slow heating, rapid heating and cooling It is the zinc ferrite material mentioned above. The zinc ferrite material prepared by the method of the invention has ultra-high saturation magnetization and can maintain good magnetic properties after high-temperature calcination.

Description

Zinc ferrite material and preparation method thereof

technical field

The invention relates to the field of magnetic materials, in particular to a zinc ferrite material and a preparation method thereof.

Background technique

Soft magnetic ferrite is a kind of magnetic functional material with a wide range of applications, and has a wide range of applications in many fields such as national defense, electronics, chemical industry, ceramics, biology and medicine.

Soft ferrite usually has the advantages of high magnetic permeability, high resistivity and low loss performance. As an important characteristic parameter of soft ferrite, saturation magnetization has a limiting effect on the magnetic permeability and resonance frequency of the material. . Existing soft ferrite materials, especially those with high magnetic permeability, are often limited in application due to low saturation magnetization. The saturation magnetization of traditional soft magnetic ferrite is usually 0.6T or lower, so the frequency of ferrite as a high permeability material is usually 1KHz to 10MHz.

With the development of miniaturization and high frequency of electronic devices, the operating frequency of soft ferrite materials is urgently required to develop in the GHz frequency band. The saturation magnetization of current soft ferrite materials cannot meet the needs, and the current soft ferrite materials The high temperature resistance of bulk materials can no longer meet the needs of development.

Contents of the invention

The object of the present invention is to provide a zinc ferrite material and a preparation method thereof. The zinc ferrite material of the invention has ultra-high saturation magnetization and can maintain good magnetic properties after high-temperature calcination.

The purpose of the present invention is accomplished through the following technical solutions.

On the one hand, an embodiment of the present invention provides a method for preparing a zinc ferrite material, comprising the following steps:

Ingredients: raw materials include iron acetylacetonate, zinc acetylacetonate, surfactant and solvent; the solvent is dibenzyl ether or 1-octadecene or oleylamine;

Wherein, the molar ratio of zinc acetylacetonate and iron acetylacetonate is 0.1～0.8, the molar ratio of the total amount of iron acetylacetonate and zinc acetylacetonate to surfactant is 0.01～0.85, and the amount of solvent can fully dissolve iron acetylacetonate and acetylacetonate Zinc;

The raw materials are placed in a protective gas environment, mixed at room temperature; and then the product particles obtained after slow heating, rapid heating and cooling are the zinc ferrite materials.

Further, the surfactant is a mixture of oleic acid and 1,2-hexadecanediol or oleic acid or stearic acid.

Further, the slow temperature rise is to raise the temperature to 110-120°C at a rate lower than 5°C/min, and keep the constant temperature for more than 0.5h;

The rapid temperature rise means that the temperature is raised to 276-365° C. at a rate higher than 7.5° C./min, and the high-temperature reaction exceeds 20 minutes.

Further, the heating rate of the slow heating up is 2-4°C/min;

The rapid temperature rise is a temperature rise rate of 10-15° C./min to a temperature of 278-282° C.

Further, the molar ratio of zinc acetylacetonate to iron acetylacetonate is 0.3-0.6; the molar ratio of the total amount of iron acetylacetonate and zinc acetylacetonate to the surfactant is 0.4-0.6; the amount of the solvent is 3 to 20 times the molar amount of active agent.

Further, the amount of the solvent used is 5-12 times the molar amount of the surfactant.

Further, the product particles are washed with an organic solvent and collected.

Further, the organic solvent is hexane, toluene, ethanol or methanol.

In the second aspect, the embodiment of the present invention provides a zinc ferrite material, the chemical formula of the zinc ferrite material is: Zn _X Fe _3-X O ₄ ; wherein: 0<X<0.53.

Further, the zinc ferrite material is prepared by the above-mentioned preparation method, the normal temperature saturation magnetization of the zinc ferrite material is 90-120emu/g, the Curie temperature is ≥400°C, and the material is stored in an oxygen-free environment. After calcination at 600-1200°C, the saturation magnetization at room temperature decreases by no more than 5% of the saturation magnetization before calcination.

Compared with the prior art, the zinc ferrite material of the present invention and its preparation method have at least the following advantages:

The proportion of iron and zinc is controlled through the reasonable ratio of iron acetylacetonate and zinc acetylacetonate and formula design; the protective gas is evacuated and the temperature is kept at high temperature for a period of time to ensure that the air in the reaction device is emptied and the raw materials are fully dissolved, and the temperature is further rapidly raised to 280 ℃, oleic acid, as a surfactant, helps to control the content of iron and zinc in the product particles and the distribution in the crystal structure during the high-temperature reaction, which plays a key role in the saturation magnetization of soft ferrite.

Compared with the existing products, the ultra-high saturation magnetization and high temperature resistant zinc ferrite material of the present invention has greatly improved the saturation magnetization, and the material remains good after being calcined at a high temperature in an oxygen-free environment Excellent magnetic properties, the Curie temperature of the material exceeds 400°C.

detailed description

For the convenience of those skilled in the art to understand the solution of the present invention, the following description will be made in conjunction with the preferred embodiments. It should be understood that the preferred embodiments are to explain the technical solution of the present invention, rather than limit the scope of protection.

A preparation method of zinc ferrite material, comprising the steps of:

Ingredients: raw materials include iron acetylacetonate, zinc acetylacetonate, surfactant and solvent; the solvent is dibenzyl ether or 1-octadecene or oleylamine;

Wherein, the molar ratio of zinc acetylacetonate and iron acetylacetonate is 0.1～0.8, the molar ratio of the total amount of iron acetylacetonate and zinc acetylacetonate to surfactant is 0.01～0.85, and the amount of solvent can fully dissolve iron acetylacetonate and acetylacetonate Zinc;

The raw materials are placed in a protective gas environment, mixed at room temperature; and then the product particles obtained after slow heating, rapid heating and cooling are the zinc ferrite materials.

The chemical formula of the zinc ferrite material prepared by the above method is: Zn _X Fe _3-X O ₄ ; wherein: 0<X<0.53.

What is to be explained here is: through the reasonable ratio of iron acetylacetonate and zinc acetylacetonate and formula design to control the ratio of iron element to zinc element; the protective gas is evacuated and the temperature is kept at high temperature for a period of time to ensure that the air in the reaction device is emptied and the raw materials are fully dissolved , the type of protective gas is not limited here, mainly for the purpose of exhausting the air and preventing the components in the air from participating in the reaction to affect the preparation of zinc ferrite materials. Generally, argon, nitrogen and other gases are used, and those skilled in the art can choose according to their needs. Suitable shielding gas.

The above schemes can already complete the preparation of zinc ferrite materials, and on this basis, the preferred scheme is given:

Preferably, the surfactant is a mixture of oleic acid and 1,2-hexadecanediol or oleic acid or stearic acid.

It should be explained here that oleic acid, as a surfactant, helps to control the content of iron and zinc in the product particles and the distribution in the crystal structure during the high-temperature reaction, which is important for the saturation magnetization of soft ferrite. its key role.

As a preference, the slow temperature rise is to raise the temperature to 110-120°C at a rate lower than 5°C/min, and keep the constant temperature for more than 0.5h;

The rapid temperature rise means that the temperature is raised to 276-365° C. at a rate higher than 7.5° C./min, and the high-temperature reaction exceeds 20 minutes.

As preferably, the heating rate of the slow heating up is 2-4°C/min;

The rapid temperature rise is a temperature rise rate of 10-15° C./min to a temperature of 278-282° C.

What should be explained here is: the heating rate of slow heating is controlled at 2-4°C/min, which is conducive to mixing and fully dissolving the raw materials, and is conducive to exhausting the air and water vapor in the reaction device.

The heating rate of rapid heating is 10-15°C/min, which is conducive to maintaining the consistency of the crystal grains during the growth process, and is beneficial to the uniform control of the composition and size of the zinc ferrite particles.

Preferably, the molar ratio of zinc acetylacetonate and iron acetylacetonate is 0.3 to 0.6; the molar ratio of the total amount of iron acetylacetonate and zinc acetylacetonate to the surfactant is 0.4 to 0.6; the amount of the solvent is the surface 3 to 20 times the molar amount of active agent.

Preferably, the amount of the solvent used is 5 to 12 times the molar amount of the surfactant.

It should be explained here that the surfactant plays a key role in the composition and crystal structure of zinc ferrite, and the reasonable amount of surfactant is conducive to the formation of zinc ferrite particles with high saturation magnetization.

Preferably, the product particles are washed with an organic solvent and collected.

Preferably, the organic solvent is hexane, toluene, ethanol or methanol.

It should be explained here that the organic solvent is beneficial to remove the zinc ferrite particle surfactant and other additives generated in the reaction, and has no destructive effect on the zinc ferrite particle.

Example 1

A zinc ferrite material and a preparation method thereof, comprising the steps of:

(1) Ingredients

Iron acetylacetonate 12mmol, zinc acetylacetonate 2mmol, dibenzyl ether 20mL, oleic acid 28mmol.

(2) Reaction

Put the raw materials in the batching (1) in the three-necked flask, and connect the temperature measuring device, ventilation device, condensation device and exhaust device.

Stir for 1 h at room temperature using a magnetic heater.

Slowly (4°C/min) raise the temperature to 120°C, and keep the constant temperature for 1h.

Rapidly (16°C/min) heat up to 280°C, react at high temperature for 0.5h and then cool naturally.

The resultant particles were washed with hexane and collected.

Performance test example:

Test object: the ultra-high saturation magnetization high temperature resistant zinc ferrite material described in Example 1, chemical formula: Zn _0.12 Fe _2.88 O ₄ .

The saturation magnetization is 94emu/g.

The Curie temperature is 400°C.

After high-temperature calcination at 1200°C for 30 minutes in an oxygen-free environment, the saturation magnetization of zinc ferrite material is 92emu/g, and after high-temperature calcination at 1200°C for 3 hours in an oxygen-free environment, the saturation magnetization of zinc ferrite is 90emu /g.

Example 2:

(1) Ingredients

Iron acetylacetonate 12mmol, zinc acetylacetonate 8.5mmol, dibenzyl ether 20mL, oleic acid 28mmol.

(2) Reaction

a) Put the raw materials in the ingredient (1) in a three-necked flask, and connect the temperature measuring device, ventilation device, condensing device and exhaust device.

b) Stir for 1 h at room temperature using a magnetic heater.

c) Raise the temperature slowly (5°C/min) to 120°C, and keep the temperature constant for 1h.

d) Rapidly (16°C/min) heat up to 280°C, react at high temperature for 0.5h and cool down naturally.

e) Wash the product particles with toluene and collect them.

Performance test example:

Test object: the ultra-high saturation magnetization high temperature resistant zinc ferrite material described in Example 2, chemical formula: Zn _0.48 Fe _2.52 O ₄ .

The saturation magnetization is 120emu/g.

The Curie temperature is 402°C.

After high-temperature calcination at 1200° C. for 1 hour in an oxygen-free environment, the high saturation magnetization zinc ferrite material is 115 emu/g.

Example 3:

(1) Ingredients

Iron acetylacetonate 12mmol, zinc acetylacetonate 10mmol, dibenzyl ether 20mL, oleic acid 28mmol.

(2) Reaction

a) Put the raw materials in the ingredient (1) in a three-necked flask, and connect the temperature measuring device, ventilation device, condensing device and exhaust device.

b) Stir for 1 h at room temperature using a magnetic heater.

c) Raise the temperature slowly (5°C/min) to 110°C, and keep the temperature constant for 1h.

d) Rapidly (17°C/min) heat up to 280°C, react at high temperature for 0.5h and cool down naturally.

e) Wash the product particles with hexane and collect them.

Performance test example:

Test object: the ultra-high saturation magnetization high temperature resistant zinc ferrite material described in Example 3, chemical formula: Zn _0.51 Fe _2.49 O ₄ .

The saturation magnetization is 104emu/g.

The Curie temperature is 402°C.

After high-temperature calcination at 1200° C. for 1 hour in an oxygen-free environment, the high saturation magnetization zinc ferrite material is 100 emu/g.

The raw materials described in Examples 1-3 are all commercially available products, and the amount of each component is increased or decreased according to the same ratio, and the relationship of parts by weight of each component obtained falls within the protection scope of the present invention.

For the collection of the product, those skilled in the art can select organic solvents such as hexane, toluene, ethanol or methanol, etc. that can be used to collect the product of the present invention as required.

Where the application of the present invention is not exhausted, those skilled in the art can use the existing conventional technology to complete it according to the existing knowledge and needs, such as which reaction device to use, etc., which are not limited here.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (10)

1. a kind of preparation method of Zinc ferrite material, it is characterised in that comprise the steps：

Dispensing：Raw material includes ferric acetyl acetonade, zinc acetylacetonate, surfactant and solvent；Described solvent be benzyl ether or 1- octadecanes alkene or oleyl amine；

Wherein, the molar ratio 0.1～0.8 of zinc acetylacetonate and ferric acetyl acetonade, ferric acetyl acetonade and zinc acetylacetonate it is total Amount is 0.01～0.85 with the mol ratio of surfactant, and the amount of solvent can fully dissolve ferric acetyl acetonade and zinc acetylacetonate；

Described raw material is placed in protective gas environment, normal temperature is mixed；Then obtain Jing after heating up at a slow speed, be rapidly heated and cool down The composition granule that generates for arriving is described Zinc ferrite material.

2. the preparation method of Zinc ferrite material according to claim 1, it is characterised in that described surfactant is The mixture or oleic acid or stearic acid of oleic acid and 1,2- hexadecane diol.

3. the preparation method of Zinc ferrite material according to claim 1, it is characterised in that described intensification at a slow speed is low 110～120 DEG C are warmed up in the programming rate of 5 DEG C/min, constant temperature is continued above 0.5h；

Described being rapidly heated is that programming rate higher than 7.5 DEG C/min is warmed up to 276-365 DEG C, and pyroreaction is more than 20min.

4. the preparation method of Zinc ferrite material according to claim 3, it is characterised in that the described liter for heating up at a slow speed Warm speed is 2-4 DEG C/min；

The described programming rate being rapidly heated as 10-15 DEG C/min is warmed up to temperature for 278-282 DEG C.

5. the preparation method of Zinc ferrite material according to claim 1, it is characterised in that zinc acetylacetonate and levulinic The mol ratio of ketone iron is 0.3～0.6；The total amount of the ferric acetyl acetonade and zinc acetylacetonate is with the mol ratio of surfactant 0.4～0.6；The consumption of described solvent is 3～20 times of surfactant mole.

6. the preparation method of Zinc ferrite material according to claim 5, it is characterised in that the consumption of described solvent is 5～12 times of surfactant mole.

7. the preparation method of Zinc ferrite material according to claim 1, it is characterised in that generation is cleaned with organic solvent Composition granule, and collect.

8. the preparation method of Zinc ferrite material according to claim 7, it is characterised in that described organic solvent is for oneself Alkane, toluene, ethanol or methyl alcohol.

9. a kind of Zinc ferrite material, it is characterised in that the chemical formula of described Zinc ferrite material is：Zn_XFe_3-XO₄；Wherein： 0 ＜ X ＜ 0.53.

10. Zinc ferrite material according to claim 9, it is characterised in that described Zinc ferrite material will by right Ask the preparation method described in any one of 1-8 to be prepared, the Zinc ferrite material normal temperature saturation magnetization be 90～ 120emu/g, Curie temperature >=400 DEG C, under oxygen-free environment after 600-1200 DEG C of calcining, normal temperature saturation magnetization drops material It is low less than 5% of the magnetic saturation intensity of magnetization before calcining.