CN105236745A - A kind of ferromagnetic Fe3O4 nano glass ceramics and its preparation method - Google Patents

Abstract

A ferromagnetic Fe ₃ O ₄ nano glass-ceramic and its preparation method, comprising mixing barium oxide, iron oxide, boron oxide, silicon dioxide, cerium oxide and antimony oxide according to a certain chemical ratio and mixing them uniformly to obtain Batch materials; then melt the batch materials into molten glass, and keep it warm for a period of time to clarify and homogenize the molten glass; then quickly pour the molten glass into a heated mold to form it, and after it is formed, it will be quickly Transfer to the annealing furnace for annealing treatment and then cool with the furnace, and finally cut and process it into a certain shape, put it on an alumina plate and put it in a muffle furnace to raise it to the required temperature and keep it warm, and then cool with the furnace. The method has the advantages of simple operation, short preparation cycle, low cost, and the raw materials used in the preparation process are all environmentally friendly, which conforms to the concept of green environmental protection; the prepared ferromagnetic Fe ₃ O ₄ has small size, high crystal purity, and few impurity phases And the composition is dense.

Description

A kind of ferromagnetic Fe3O4 nano glass ceramics and its preparation method

technical field

The invention belongs to the technical field of magnetic glass-ceramics preparation, and relates to a ferromagnetic _Fe3O4 nano _- glass-ceramics and a preparation method thereof.

Background technique

Glass-ceramics, also known as glass ceramics, is a kind of polycrystalline solid material containing a large number of microcrystalline phases and glass phases, which is obtained by controlling the crystallization of a specific composition of basic glass during the heating process. The comprehensive performance of glass-ceramics is mainly determined by three factors: the composition of the original composition, the size and quantity of crystallites, and the nature and quantity of the residual glass phase. Among them, the original composition is different, and the types of crystal phases are also different, and various crystal phases endow glass-ceramics with different functions. In recent years, with the continuous development of modern science and technology, the performance requirements of materials are getting higher and higher. Glass-ceramic has many excellent properties such as low density, dense texture without pores, good chemical stability, and excellent electrical properties. In recent years, the research on glass-ceramics has become a new development direction in the field of functional materials research in recent years.

Magnetite (Fe ₃ O ₄ ) is an inverse spinel crystal structure composed of Fe ²⁺ , Fe ³⁺ and O ^2- . Its special structure allows electrons to transfer between Fe ²⁺ and Fe ³⁺ , which has special electromagnetic properties. It has high saturation magnetization, high Curie temperature and strong conductivity. As a multifunctional magnetic material, it has a wide range of applications in the fields of magnetic fluid, microwave absorbing materials, catalyst carriers, and magnetic recording materials. At present, the preparation methods of magnetic Fe ₃ O ₄ nanoparticles are divided into chemical methods and physical methods, among which chemical methods include hydrolysis method, precipitation method, microemulsion method, hydrothermal method, sol-gel method and so on. The chemical method and the physical method have their own advantages in the process of powder preparation, but the disadvantages are that the production cost is high, the cycle is long, and the prepared powder is easy to agglomerate, which makes it unfavorable for industrial production.

Contents of the invention

The object of the present invention is to provide a ferromagnetic Fe ₃ O ₄ nano glass-ceramic and its preparation method. The preparation process of the method is simple, the material cost is low, it is suitable for industrial production, and the prepared material has excellent magnetic properties.

To achieve the above object, the present invention takes the following technical solutions:

A ferromagnetic Fe ₃ O ₄ nanocrystal glass, comprising 10-20 parts of BaO, 10-20 parts of Fe ₂ O ₃ , 10-50 parts of B ₂ O ₃ , 10-50 parts by mass in terms of parts by mass. parts of SiO ₂ , 0.1-1 parts of CeO ₂ and 0.1-0.3 parts of Sb ₂ O ₃ ; wherein the sum of the parts by mass of BaO, Fe ₂ O ₃ , B ₂ O ₃ and SiO ₂ is 100 parts.

In terms of parts by mass, it includes 10-30 parts of BaO, 15-20 parts of Fe ₂ O ₃ , 30-50 parts of B ₂ O ₃ , 10-30 parts of SiO ₂ , 0.1-1 part of CeO ₂ and 0.1-0.3 parts of Sb ₂ O ₃ ; wherein the sum of the parts by mass of BaO, Fe ₂ O ₃ , B ₂ O ₃ and SiO ₂ is 100 parts.

In terms of parts by mass, it includes 30-50 parts of BaO, 10-15 parts of Fe ₂ O ₃ , 10-30 parts of B ₂ O ₃ , 30-50 parts of SiO ₂ , 0.1-1 part of CeO ₂ and 0.1-0.3 parts of Sb ₂ O ₃ ; wherein the sum of the parts by mass of BaO, Fe ₂ O ₃ , B ₂ O ₃ and SiO ₂ is 100 parts.

A preparation method of ferromagnetic Fe ₃ O ₄ nano glass ceramics, comprising the following steps:

Step 1: In terms of parts by mass, 10-20 parts of BaO, 10-20 parts of Fe ₂ O ₃ , 10-50 parts of B ₂ O ₃ , 10-50 parts of SiO ₂ , and 1 part of CeO ₂ and 0.3 parts of Sb ₂ O ₃ are mixed uniformly to obtain batch materials; wherein the sum of the mass parts of BaO, Fe ₂ O ₃ , B ₂ O ₃ and SiO ₂ is 100 parts;

Step 2: Add the batch material into a corundum crucible at 1100°C, raise the temperature to 1200-1400°C, and keep it warm for 0.5-2 hours to obtain molten glass;

Step 3: Pour the molten glass onto a stainless steel plate, transfer it to an annealing furnace to keep it warm after being formed, and then cool it to room temperature with the furnace to obtain barium iron borosilicate glass;

Step 4: Cut the barium-iron-borosilicate glass into a certain shape, then keep it warm at 700°C, and then cool down to room temperature with the furnace to obtain ferromagnetic Fe ₃ O ₄ nano glass-ceramics.

In the described step one, BaO is introduced by analytically pure barium carbonate.

In the first step, B ₂ O ₃ is introduced by analytically pure boric acid.

The temperature in the annealing furnace in the step 3 is 400-600°C.

The heat preservation time in the annealing furnace in the step 3 is 2 to 4 hours.

In the fourth step, the temperature is raised from room temperature to 700° C. at a rate of 10° C./min.

The heat preservation time in the step 4 is 4 to 6 hours.

Compared with the prior art, the present invention has beneficial effects: firstly, the present invention mixes barium oxide, iron oxide, boron oxide, silicon dioxide, cerium oxide and antimony oxide according to a certain chemical ratio and mixes them evenly to obtain Batch materials; then melt the batch materials into molten glass, and keep it warm for a period of time to clarify and homogenize the molten glass; then quickly pour the molten glass into a heated mold to form it, and after it is formed, it will be quickly Transfer to the annealing furnace for annealing treatment and then cool with the furnace to obtain barium iron borosilicate glass; finally, the obtained glass block is cut into a certain shape, placed on an alumina plate and placed in a muffle furnace Raise to the required temperature and heat preservation treatment, after cooling with the furnace, the ferromagnetic Fe ₃ O ₄ nano glass-ceramics can be obtained. In the present invention, raw materials are added at high temperature, the high-temperature melting process is performed, and the batch material is placed in a corundum crucible, which avoids the influence of uneven composition caused by the volatilization of boric _{acid ;} CeO2 is used as a nucleating agent in the present invention, and the introduction of CeO2 is beneficial The precipitation of crystal phase in the process of crystallization of glass-ceramics; Sb ₂ O ₃ as a clarifying agent, the introduction of Sb ₂ O ₃ is conducive to the elimination of bubbles in the ferromagnetic glass liquid during high-temperature melting, ensuring that the obtained glass has no bubbles, etc. defect. In the present invention, the purpose of adding batch materials at 1100°C is to prevent the volatilization of boric acid in the batch materials during the heating process and affect the glass composition, so the feeding is carried out at a temperature slightly lower than the melting temperature. In addition, the addition of boric acid helps to reduce the melting temperature of the glass, and with the increase of boric acid content, the melting temperature of the glass decreases. The method has the advantages of simple operation, short preparation cycle, low cost, and the raw materials used in the preparation process are all environmentally friendly, which conforms to the concept of green environmental protection; the prepared ferromagnetic Fe ₃ O ₄ has small size, high crystal purity, and few impurity phases And the composition is dense. The saturation magnetization of ferromagnetic Fe ₃ O ₄ is 21.860emu/g, the coercive force is 303.658Oe, and the residual magnetization is 6.647emu/g.

Compared with the usual ceramic forming process, the overall crystallization method of the present invention is more suitable for automatic operation and preparation of products with complex shapes and precise dimensions; the crystallized glass prepared by the glass body has little change in size, uniform composition, and no Common defects in ceramics such as pores are present. Therefore, this method opens up a new world for the preparation of new glass-ceramic materials. The present invention adopts the overall crystallization method to prepare ferromagnetic Fe ₃ O ₄ nano glass-ceramics, uses low raw material prices, is energy-saving and environmentally friendly, and is suitable for industrial production. The overall crystallization method can be used as a method for preparing ferromagnetic Fe ₃ O ₄ nanoparticles Useful ways.

Description of drawings

Fig. ₁ is the XRD spectrum of the ferromagnetic _Fe3O4 nano glass ceramics of the present invention.

Fig. 2 is a photograph under a scanning electron microscope of the ferromagnetic Fe ₃ O ₄ nano glass-ceramics of the present invention after polishing and heat-etching treatment.

Fig. 3 is a hysteresis loop of the ferromagnetic Fe ₃ O ₄ nano glass-ceramic of the present invention, wherein the abscissa is the magnetic field intensity, and the ordinate is the magnetization intensity.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and through specific embodiments.

The present invention adopts integral crystallization method to prepare ferromagnetic Fe ₃ O ₄ The preparation method of nano glass-ceramics is specifically as follows:

Example 1

Step 1: Mix analytically pure barium carbonate, analytically pure boric acid, SiO ₂ , CeO ₂ and Sb ₂ O ₃ , so that in terms of parts by mass, 20 parts of BaO, 20 parts of Fe ₂ O ₃ , 10 parts of B ₂ O ₃ , 50 parts of SiO ₂ , 0.3 parts of CeO ₂ and 0.2 parts of Sb ₂ O ₃ were mixed uniformly to obtain batch materials;

Step 2: Add the uniformly mixed batch material into a corundum crucible with a cover at 1100°C, heat up to 1400°C for melting to form molten glass, and keep warm at 1400°C for 1 hour to obtain clear and homogeneous glass liquid;

Step 3: Quickly pour the molten glass onto a stainless steel plate, transfer it to an annealing furnace at 500°C immediately after forming, keep it at 500°C for 2 hours, and then cool to room temperature with the furnace to obtain barium iron borosilicate glass;

Step 4: Cut the barium iron borosilicate glass into a certain shape, place the cut sample on the alumina plate and put it in the muffle furnace, and heat it from room temperature to 700 °C at a heating rate of 10 °C/min for 4 hours Then cool down to room temperature with the furnace to obtain ferromagnetic Fe ₃ O ₄ nano glass-ceramics.

FIG. 1 is the XRD spectrum of the ferromagnetic Fe ₃ O ₄ nano glass ceramics prepared in Example 1. It can be seen from the figure that the prepared crystals are of high purity.

FIG. 2 is a SEM photo of the ferromagnetic Fe ₃ O ₄ nano glass ceramics prepared in Example 1. It can be seen from the figure that a large number of nano-sized crystals are precipitated with a relatively uniform distribution.

Fig. 3 is the hysteresis loop of the ferromagnetic Fe ₃ O ₄ nano glass-ceramics in Example 1. The specific saturation magnetization of the Fe ₃ O ₄ nano glass-ceramic is 21.860emu/g, the coercive force is 303.658Oe, and the residual magnetization is 6.647emu/g.

Example 2

Step 1: Mix analytically pure barium carbonate, analytically pure boric acid, SiO ₂ , CeO ₂ and Sb ₂ O ₃ , so that 20 parts of BaO, 20 parts of Fe ₂ O ₃ , 20 parts of B ₂ O ₃ , 40 parts of SiO ₂ , 0.3 parts of CeO ₂ and 0.2 parts of Sb ₂ O ₃ were mixed uniformly to obtain batch materials;

Step 2: Add the uniformly mixed batch material into a corundum crucible with a cover at 1100°C, heat up to 1350°C for melting to form molten glass, and keep warm at 1350°C for 1 hour to obtain a clear and homogeneous molten glass ;

Step 3: Quickly pour the evenly melted molten glass onto a stainless steel plate, transfer it to an annealing furnace at 500°C immediately after forming, keep it warm for 2 hours, and then cool down to room temperature with the furnace to obtain barium iron borosilicate glass;

Step 4: Cut the prepared barium iron borosilicate glass into a certain shape, put the cut sample on the alumina plate and put it in the muffle furnace, and raise the temperature from room temperature to 700 °C at a heating rate of 10 °C/min After heat preservation for 4 hours, the ferromagnetic Fe ₃ O ₄ nano glass-ceramics can be obtained by cooling down to room temperature with the furnace.

Example 3

Step 1: Mix analytically pure barium carbonate, analytically pure boric acid, SiO ₂ , CeO ₂ and Sb ₂ O ₃ , so that 20 parts of BaO, 20 parts of Fe ₂ O ₃ , 30 parts of B ₂ O ₃ , 30 parts of SiO ₂ , 0.3 parts of CeO ₂ and 0.2 parts of Sb ₂ O ₃ were mixed uniformly to obtain batch materials;

Step 2: Add the uniformly mixed batch material into a corundum crucible with a cover at 1100°C, heat up to 1300°C for melting to form molten glass, and keep warm at 1300°C for 1 hour to obtain a clear and homogeneous molten glass ;

Step 3: Quickly pour the evenly melted molten glass onto a stainless steel plate, transfer it to an annealing furnace at 500°C immediately after forming, keep it warm for 2 hours, and then cool down to room temperature with the furnace to obtain barium iron borosilicate glass;

Step 4: Cut the prepared barium iron borosilicate glass into a certain shape, put the cut sample on the alumina plate and put it in the muffle furnace, and raise the temperature from room temperature to 700 °C at a heating rate of 10 °C/min After heat preservation for 4 hours, the ferromagnetic Fe ₃ O ₄ nano glass-ceramics can be obtained by cooling down to room temperature with the furnace.

Example 4

Step 1: Mix analytically pure barium carbonate, analytically pure boric acid, SiO ₂ , CeO ₂ and Sb ₂ O ₃ , so that 20 parts of BaO, 20 parts of Fe ₂ O ₃ , 40 parts of B ₂ O ₃ , 20 parts of SiO ₂ , 0.3 parts of CeO ₂ and 0.2 parts of Sb ₂ O ₃ were mixed uniformly to obtain batch materials;

Step 2: Add the uniformly mixed batch material into a corundum crucible with a cover at 1100°C, heat up to 1250°C for melting to form molten glass, and keep warm at 1250°C for 1 hour to obtain a clear and homogeneous molten glass ;

Step 3: Quickly pour the evenly melted molten glass onto a stainless steel plate, transfer it to an annealing furnace at 500°C immediately after forming, keep it warm for 2 hours, and then cool down to room temperature with the furnace to obtain barium iron borosilicate glass;

Step 4: Cut the prepared barium iron borosilicate glass into a certain shape, put the cut sample on the alumina plate and put it in the muffle furnace, and raise the temperature from room temperature to 700 °C at a heating rate of 10 °C/min After heat preservation for 4 hours, the ferromagnetic Fe ₃ O ₄ nano glass-ceramics can be obtained by cooling down to room temperature with the furnace.

Example 5

Step 1: Mix analytically pure barium carbonate, analytically pure boric acid, SiO ₂ , CeO ₂ and Sb ₂ O ₃ , so that in terms of parts by mass, 20 parts of BaO, 20 parts of Fe ₂ O ₃ , 50 parts of B ₂ O ₃ , 10 parts of SiO ₂ , 0.3 parts of CeO ₂ and 0.2 parts of Sb ₂ O ₃ were mixed uniformly to obtain batch materials;

Step 2: Add the uniformly mixed batch material into a corundum crucible with a cover at 1100°C, heat up to 1200°C for melting to form molten glass, and keep warm at 1200°C for 1 hour to obtain a clear and homogeneous molten glass ;

Step 3: Quickly pour the evenly melted molten glass onto a stainless steel plate, transfer it to an annealing furnace at 500°C immediately after forming, keep it warm for 2 hours, and then cool down to room temperature with the furnace to obtain barium iron borosilicate glass;

Step 4: Cut the prepared barium iron borosilicate glass into a certain shape, put the cut sample on the alumina plate and put it in the muffle furnace, and raise the temperature from room temperature to 700 °C at a heating rate of 10 °C/min After heat preservation for 4 hours, the ferromagnetic Fe ₃ O ₄ nano glass-ceramics can be obtained by cooling down to room temperature with the furnace.

Example 6

Step 1: Mix analytically pure barium carbonate, analytically pure boric acid, SiO ₂ , CeO ₂ and Sb ₂ O ₃ , so that in terms of parts by mass, 10 parts of BaO, 18 parts of Fe ₂ O ₃ , 42 parts B ₂ O ₃ , 30 parts of SiO ₂ , 0.1 part of CeO ₂ and 0.3 part of Sb ₂ O ₃ were mixed uniformly to obtain batch materials;

Step 2: Add the uniformly mixed batch material into a corundum crucible with a cover at 1100°C, heat up to 1250°C for melting to form molten glass, and keep warm at 1250°C for 1.5h to obtain clear and homogeneous glass liquid;

Step 3: Quickly pour the evenly melted molten glass onto a stainless steel plate, transfer it to an annealing furnace at 400°C immediately after forming, keep it warm for 4 hours, and then cool to room temperature with the furnace to obtain barium iron borosilicate glass;

Step 4: Cut the prepared barium iron borosilicate glass into a certain shape, put the cut sample on the alumina plate and put it in the muffle furnace, and raise the temperature from room temperature to 700 °C at a heating rate of 10 °C/min After heat preservation for 5 hours, the ferromagnetic Fe ₃ O ₄ nano glass-ceramics can be obtained by cooling down to room temperature with the furnace.

Example 7

Step 1: Mix analytically pure barium carbonate, analytically pure boric acid, SiO ₂ , CeO ₂ and Sb ₂ O ₃ , so that in terms of parts by mass, 15 parts of BaO, 10 parts of Fe ₂ O ₃ , 50 parts of B ₂ O ₃ , 25 parts of SiO ₂ , 0.6 part of CeO ₂ and 0.1 part of Sb ₂ O ₃ were mixed uniformly to obtain batch materials;

Step 2: Add the uniformly mixed batch material into a corundum crucible with a cover at 1100°C, heat up to 1200°C for melting to form molten glass, and keep warm at 1200°C for 0.5h to obtain clear and homogeneous glass liquid;

Step 3: Quickly pour the evenly melted molten glass onto a stainless steel plate, transfer it to an annealing furnace at 600°C immediately after forming, keep it warm for 3 hours, and then cool to room temperature with the furnace to obtain barium iron borosilicate glass;

Step 4: Cut the prepared barium iron borosilicate glass into a certain shape, put the cut sample on the alumina plate and put it in the muffle furnace, and raise the temperature from room temperature to 700 °C at a heating rate of 10 °C/min After heat preservation for 3 hours, the ferromagnetic Fe ₃ O ₄ nano glass-ceramics can be obtained by cooling down to room temperature with the furnace.

Example 8

Step 1: Mix analytically pure barium carbonate, analytically pure boric acid, SiO ₂ , CeO ₂ and Sb ₂ O ₃ , so that in terms of parts by mass, 10 parts of BaO, 10 parts of Fe ₂ O ₃ , 35 parts of B ₂ O ₃ , 45 parts of SiO ₂ , 1 part of CeO ₂ and 0.2 part of Sb ₂ O ₃ were mixed uniformly to obtain batch materials;

Step 2: Add the uniformly mixed batch material into a corundum crucible with a cover at 1100°C, heat up to 1350°C for melting to form molten glass, and keep warm at 1350°C for 1 hour to obtain a clear and homogeneous molten glass ;

Step 3: Quickly pour the evenly melted molten glass onto a stainless steel plate, transfer it to an annealing furnace at 500°C immediately after forming, keep it warm for 2 hours, and then cool down to room temperature with the furnace to obtain barium iron borosilicate glass;

Step 4: Cut the prepared barium iron borosilicate glass into a certain shape, put the cut sample on the alumina plate and put it in the muffle furnace, and raise the temperature from room temperature to 700 °C at a heating rate of 10 °C/min After heat preservation for 4 hours, the ferromagnetic Fe ₃ O ₄ nano glass-ceramics can be obtained by cooling down to room temperature with the furnace.

The preparation of ferromagnetic Fe ₃ O ₄ nano glass-ceramics by adopting the bulk crystallization method is simple in operation, low in price of raw materials, energy-saving and environment-friendly, and suitable for industrial production. It can be seen that the preparation of ferromagnetic glass-ceramics by bulk crystallization method has certain research value.

The invention avoids the influence of uneven composition caused by the volatilization of boric acid by placing the batch material in a corundum crucible with a cover; the method has simple operation, short preparation cycle, low cost, and the raw materials used in the preparation process belong to environmental protection Friendly, in line with the concept of green environmental protection; the prepared ferromagnetic Fe ₃ O ₄ has small size, high crystal purity, few impurity phases and dense composition. The overall crystallization method can be used as a method for preparing ferromagnetic Fe ₃ O ₄ nanoparticles effective method.

In the present invention, barium carbonate, iron oxide, boric acid, silicon dioxide, cerium oxide and antimony oxide are firstly prepared according to a certain chemical ratio and mixed uniformly to obtain a batch; then the batch is added and placed in a high-temperature resistance furnace in advance Melt the molten glass in a corundum crucible with a cover, and keep it warm for a period of time to clarify and homogenize the molten glass; then quickly pour the molten glass into a heated stainless steel mold to form it, and quickly Transfer to the annealing furnace for precision annealing treatment and then cool with the furnace to obtain barium iron borosilicate glass; finally, the obtained glass block is cut into a certain shape, placed on an alumina plate and placed in a muffle Raise the furnace to the desired temperature and keep it warm, and then obtain ferromagnetic Fe ₃ O ₄ nano glass-ceramics after cooling down in the furnace. In the present invention, raw materials are added at high temperature, the high-temperature melting process is performed, and the batch material is placed in a covered corundum crucible, thereby avoiding the influence of uneven composition caused by volatilization of boric acid; the method is simple in operation, short in preparation period, low in cost, The raw materials used in the preparation process are all environmentally friendly and in line with the concept of green environmental protection; the prepared ferromagnetic Fe ₃ O ₄ has small size, high crystal purity, few impurity phases and dense composition, and the overall crystallization method can be used as a preparation method. An efficient method for ferromagnetic Fe ₃ O ₄ nanoparticles.

Claims (10)

1. A ferromagnetic Fe ₃ O ₄ nano glass-ceramic, characterized in that: in terms of parts by mass, it comprises 10-20 parts of BaO, 10-20 parts of Fe ₂ O ₃ , and 10-50 parts of B ₂ O ₃ , 10-50 parts of SiO ₂ , 0.1-1 part of CeO ₂ and 0.1-0.3 parts of Sb ₂ O ₃ ; the sum of the parts by mass of BaO, Fe ₂ O ₃ , B ₂ O ₃ and SiO ₂ for 100 copies. 2. A ferromagnetic Fe ₃ O ₄ nano glass-ceramic according to claim 1, characterized in that: in terms of parts by mass, it comprises 10-30 parts of BaO, 15-20 parts of Fe ₂ O ₃ , 30-50 parts of B ₂ O ₃ , 10-30 parts of SiO ₂ , 0.1-1 part of CeO ₂ and 0.1-0.3 parts of Sb ₂ O ₃ ; where BaO, Fe ₂ O ₃ , B ₂ O ₃ , SiO The sum of the parts by mass of ₂ is 100 parts. 3. A ferromagnetic Fe ₃ O ₄ nano glass-ceramic according to claim 1, characterized in that: in terms of parts by mass, it comprises 30-50 parts of BaO, 10-15 parts of Fe ₂ O ₃ , 10-30 parts of B ₂ O ₃ , 30-50 parts of SiO ₂ , 0.1-1 part of CeO ₂ and 0.1-0.3 parts of Sb ₂ O ₃ ; where BaO, Fe ₂ O ₃ , B ₂ O ₃ , SiO The sum of the parts by mass of ₂ is 100 parts. 4. a ferromagnetic Fe ₃ O ₄ preparation method of nanometer glass-ceramic, it is characterized in that, comprises the following steps: Step 1: In terms of parts by mass, 10-20 parts of BaO, 10-20 parts of Fe ₂ O ₃ , 10-50 parts of B ₂ O ₃ , 10-50 parts of SiO ₂ , and 1 part of CeO ₂ and 0.3 parts of Sb ₂ O ₃ are mixed uniformly to obtain batch materials; wherein the sum of the mass parts of BaO, Fe ₂ O ₃ , B ₂ O ₃ and SiO ₂ is 100 parts; Step 2: Add the batch material into a corundum crucible at 1100°C, raise the temperature to 1200-1400°C, and keep it warm for 0.5-2 hours to obtain molten glass; Step 3: Pour the molten glass onto a stainless steel plate, transfer it to an annealing furnace to keep it warm after being formed, and then cool it to room temperature with the furnace to obtain barium iron borosilicate glass; Step 4: Cut the barium-iron-borosilicate glass into a certain shape, then keep it warm at 700°C, and then cool down to room temperature with the furnace to obtain ferromagnetic Fe ₃ O ₄ nano glass-ceramics. 5. The method for preparing ferromagnetic Fe ₃ O ₄ nano glass-ceramics according to claim 4, characterized in that: in the first step, BaO is introduced from analytically pure barium carbonate. 6. The method for preparing ferromagnetic Fe ₃ O ₄ nano glass-ceramics according to claim 4, characterized in that: in the first step, B ₂ O ₃ is introduced by analytically pure boric acid. 7. The method for preparing ferromagnetic Fe ₃ O ₄ nano glass-ceramics according to claim 4, characterized in that: the temperature in the annealing furnace in the third step is 400-600°C. 8. The method for preparing ferromagnetic Fe ₃ O ₄ nano glass-ceramics according to claim 4 or 7, characterized in that: in the step 3, the holding time in the annealing furnace is 2-4 hours. 9. The method for preparing ferromagnetic Fe ₃ O ₄ nano glass-ceramics according to claim 4, characterized in that in step 4, the temperature is raised from room temperature to 700°C at a heating rate of 10°C/min. 10. The method for preparing ferromagnetic Fe ₃ O ₄ nano glass-ceramics according to claim 4, characterized in that: the holding time in step 4 is 4-6 hours.