A Ce-doped erbium ferrite material, its preparation method and application

Abstract

This invention discloses a Ce-doped erbium ferrite material, its preparation method, and its applications. The general chemical formula of the Ce-doped erbium ferrite material is Ce. x Er 1‑x FeO3, where x ranges from 0.02 to 0.06; when 0.02 to 0.06, Ce-doped erbium ferrite material achieves bidirectional adjustable coercivity, first decreasing and then increasing, while maintaining high-frequency, low electromagnetic loss characteristics. Furthermore, Ce doping optimizes the magnetic properties of erbium ferrite. Ce-doped erbium ferrite material is black in its unground state. After light grinding in a grinding container, it turns into red particles. Further heavy grinding of the red particles or the unground Ce-doped erbium ferrite material gradually turns it into yellow particles. Simultaneously, the XRD crystal structure of the Ce-doped erbium ferrite material remains unchanged before and after grinding. This mechanical grinding achieves a black → red → yellow color change without phase transition and can be applied to anti-counterfeiting labels.

Description

Technical Field

[0001] This invention relates to the field of erbium ferrite materials and their applications, specifically a Ce-doped erbium ferrite material, its preparation method, and its applications. Background Technology

[0002] Erbium ferrite (ErFeO3) is an orthorhombic perovskite rare-earth ferrite material with an orthorhombic crystal system and space group Pbnm. This material system contains Er... 3+ and Fe 3+ Two magnetic subsystems, Fe 3+ -Fe 3+ Er 3+ -Fe 3+ Er 3+ -Er 3+ The interactions and influences between them have produced a wealth of physical phenomena. Their spin dynamics properties have attracted widespread attention in recent years, and rare earth ferrites have important application prospects in fields such as magneto-optical switches, magneto-optical isolators, magneto-optical sensors, and magnetic recording media.

[0003] In existing technologies, adding rare earth elements as dopant can effectively improve the magnetocrystalline anisotropy of ferrites and optimize their magnetic properties. However, it can only adjust the coercivity in one direction and has the drawback of high electromagnetic loss at high frequencies. This is fundamentally contradictory to the requirements of bidirectional adjustment of coercivity and low electromagnetic loss at high frequencies.

[0004] Meanwhile, this invention, while studying the influence of different Ce doping concentrations on the coercivity of ferrites, discovered a new application for anti-counterfeiting. Anti-counterfeiting technology is an important research direction in the field of materials science. Traditional anti-counterfeiting labels (such as holographic anti-counterfeiting and fluorescent anti-counterfeiting) are easily counterfeited and require specific equipment (such as ultraviolet lamps) for identification. Based on mechanoluminescent or mechanochromic smart materials, mechanical stimuli can be directly converted into visible optical signals, which has unique advantages in advanced anti-counterfeiting, structural health monitoring, and human-computer interaction. Currently known mechanochromic materials are mainly organic molecular crystals, liquid crystals, or certain coordination polymers, which are generally unstable, complex to prepare, and costly. Existing mechanochromic molecules (such as spiropyran and rhodamine) suffer from technical problems such as susceptibility to light, heat, or acid-base interference, difficulty in controlling mechanochromic behavior or inconspicuous color changes, insufficient performance stability, irreversible color changes or difficulty in color recovery, as well as complex synthesis processes, high costs, and unfavorable conditions for large-scale applications. Inorganic ceramic materials are highly anticipated due to their excellent chemical and thermal stability, but there are few reports of inorganic ferrite materials that exhibit significant and stable color changes under mild mechanical grinding while maintaining phase integrity. Summary of the Invention

[0005] Therefore, the technical problem to be solved by this invention is to provide a Ce-doped erbium ferrite material, its preparation method, and its application. This invention achieves bidirectional adjustable coercivity while maintaining high-frequency, low electromagnetic loss characteristics by adjusting the Ce doping amount, and optimizes the magnetic properties of erbium ferrite through Ce doping. Furthermore, it has been found that Ce-doped erbium ferrite materials prepared with specific Ce doping amounts exhibit a black-to-red-to-yellow color change without phase transition through mechanical grinding, which can be applied to anti-counterfeiting labels.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A Ce-doped erbium ferrite material, the general chemical formula of which is Ce x Er 1-x FeO3, where the value of x is in the range of 0.02≤x≤0.06;

[0008] When 0.02≤x≤0.06, Ce-doped erbium ferrite material achieves a decrease followed by an increase in coercivity while maintaining high-frequency and low electromagnetic loss characteristics. Furthermore, Ce-doped erbium ferrite material is black in its unground state, turns into red particles after light mechanical grinding in a grinding container, and gradually turns into yellow particles after heavy grinding of the red particles or the unground Ce-doped erbium ferrite material, while the XRD crystal structure of Ce-doped erbium ferrite material does not change before and after grinding.

[0009] The above-mentioned Ce-doped erbium ferrite material, light grinding refers to grinding for 1 to 2 minutes, and the median diameter of the red particles obtained after grinding is 50.08 ± 4.23 μm;

[0010] Heavy grinding refers to grinding for 10 to 15 minutes, after which the median diameter of the yellow particles obtained is 11.52 ± 3.83 μm.

[0011] A method for preparing Ce-doped erbium ferrite material includes the following steps:

[0012] Step A: Weigh out Fe2O3 powder, Er2O3 powder and CeO2 powder, and mix them to obtain a mixed powder;

[0013] Step B: Ball mill the mixed powder, grinding media and solvent to obtain a uniformly mixed slurry;

[0014] Step C: After drying the slurry obtained in step B, press it into shape to obtain a sheet-like blank;

[0015] Step D: Place the sheet blank in a muffle furnace and sinter it in an air atmosphere. Cool it to room temperature with the furnace to obtain the Ce-doped erbium ferrite material described above.

[0016] In the above-mentioned method for preparing Ce-doped erbium ferrite material, in step A, the molar ratio of Fe, Er, and Ce elements in Fe2O3 powder, Er2O3 powder, and CeO2 powder is 1:(1-x):x, where 0.02≤x≤0.06.

[0017] In the above-mentioned method for preparing Ce-doped erbium ferrite material, in step B, the mass ratio of mixed powder, grinding media and solvent is 1:(1-3):(1-4), wherein the grinding media is zirconia balls and the solvent is water or ethanol; the ball milling speed is 200-400 rpm and the ball milling time is 5-10 hours.

[0018] In the above-mentioned method for preparing Ce-doped erbium ferrite material, in step C, the drying temperature is 80-120℃, the drying time is 8-24 hours, and the pressing conditions are: pressure of 5-10 MPa and holding time of 5-10 minutes.

[0019] In step D, the sintering conditions are as follows: initial temperature 50℃, heating to 1450-1550℃ at a heating rate of 3-5℃ / min, and holding time 10-14 hours. Sintering under these conditions yields Ce-doped erbium ferrite material, avoiding the formation of Er3Fe5O4. 12 This affects its magnetic and electromagnetic losses.

[0020] An application of Ce-doped erbium ferrite material in anti-counterfeiting marking, wherein the Ce-doped erbium ferrite material is prepared using the above-mentioned Ce-doped erbium ferrite material or by the above-mentioned method for preparing Ce-doped erbium ferrite material.

[0021] The above-mentioned application of Ce-doped erbium ferrite material in anti-counterfeiting marking includes the production of anti-counterfeiting labels, anti-counterfeiting inks, or anti-counterfeiting films.

[0022] An application of a Ce-doped erbium ferrite material in the fabrication of intelligent strain sensors, structural health monitoring systems, or mechanical stress visualization indicators, wherein the Ce-doped erbium ferrite material is prepared using the aforementioned Ce-doped erbium ferrite material or by the aforementioned method for preparing the Ce-doped erbium ferrite material.

[0023] An application of Ce-doped erbium ferrite material in magnetic storage devices, magnetic sensor devices, or spintronic devices, wherein the Ce-doped erbium ferrite material described above or the Ce-doped erbium ferrite material prepared by the method described above is used as a magnetic storage material.

[0024] The technical solution of the present invention achieves the following beneficial technical effects:

[0025] (1) The present invention obtains Ce-doped erbium ferrite material by using a specific Ce doping amount (0.02 ≤ x ≤ 0.06) and calcination temperature, thus avoiding the formation of Er3Fe5O 12 This affects its magnetic properties and electromagnetic losses. This invention addresses this by doping with an appropriate amount of Ce element, making Ce... 4+ / Ce 3+ Ion substitution Er 3+ By altering the cation distribution, Fe2+ was regulated. 3+ -O 2- -Fe 3+ The intensity of the superexchange interaction and the magnetocrystalline anisotropy field, thereby bidirectionally modulating the coercivity; Ce 4+ / Ce 3+ The presence of mixed valence states introduces a suitable amount of oxygen vacancies. The increase in oxygen vacancies leads to an increase in the real part of the dielectric, but the dielectric loss remains almost unchanged and no new loss mechanism is introduced, resulting in a low electromagnetic loss tangent. Therefore, this invention achieves bidirectional adjustable coercivity while maintaining low high-frequency electromagnetic loss.

[0026] Furthermore, this invention discovered that in Ce-doped erbium ferrite materials prepared with specific Ce doping amounts (0.02≤x≤0.06), the material size can be altered through varying degrees of mechanical grinding. This allows the color of the Ce-doped erbium ferrite material to change sequentially from its original black color (median diameter 114.30±3.83μm) to red particles (large particles with a median diameter of 50.08±4.23μm), and then to yellow particles (small particles with a median diameter of 11.52±3.83μm). The Ce doping size varies before and after mechanical grinding. x Er 1-x The XRD crystal structure of FeO3 material remains unchanged; the color change is caused by a size effect, rather than a phase transition or molecular structure change as in traditional mechanochromic materials. This invention utilizes this unique "multi-level mechanochromic" characteristic, achieving multi-level color development through grinding and crushing, thus providing a novel, stable, and visual anti-counterfeiting label. This invention offers three clear visual states: "black → red → yellow," with obvious color changes that can be identified without instruments such as ultraviolet lamps. This multi-level, continuous color change, directly related to the material's size change caused by grinding time, is difficult to replicate through simple printing or chemical dyeing, resulting in a very high level of anti-counterfeiting. Furthermore, the color change is reversible after mechanical grinding, and recovery is convenient; the original color can be restored simply by re-pressing and annealing, resulting in lower cost and process difficulty, facilitating industrial production. Moreover, Ce-doped erbium ferrite material prepared with a specific Ce doping amount (0.02≤x≤0.06) exhibits improved magnetic properties compared to erbium ferrite material, which can also be used for recycling when applied to anti-counterfeiting.

[0027] (2) This invention discovers that Ce doping amount has a non-unidirectional effect on coercivity. When the Ce doping amount x is in the range of 0.02-0.04, the coercivity of the material is significantly reduced (the reduction can reach about 37%-42%), while all of them satisfy the high-frequency magnetic loss tangent tanδ. μ ≤0.0225, High-frequency dielectric loss tangent tanδ 𝜀 <0.01. Simultaneously, when x reaches approximately 0.02, the coercivity drops to its lowest value; when x continues to increase to above 0.04, the coercivity begins to rise again. This non-unidirectional adjustment characteristic of "first decreasing and then increasing" allows the coercivity to be bidirectionally controlled within a certain range by adjusting the Ce doping amount, meeting the differentiated coercivity requirements of different magnetic storage devices while maintaining high-frequency, low electromagnetic loss characteristics.

[0028] (3) The process of this invention is simple and low-cost. It adopts the traditional solid-state sintering method (ball milling → pressing → high-temperature sintering) without the need for complex wet chemical methods such as hydrothermal, sol-gel, and microwave-assisted processes. It does not require special equipment and is suitable for large-scale industrial production. The raw materials are common oxide powders, which are inexpensive. Attached Figure Description

[0029] Figure 1 Ce obtained by the present invention x Er 1-x XRD patterns of FeO3 (x=0.00, 0.02, 0.04, 0.06) in its unground state, local micro-ends in the middle of the unground state, and powder after heavy grinding;

[0030] Figure 2 In the middle: (a) is ErFeO3, (b) is Ce 0.02 Er 0.98 FeO3, (c) is Ce 0.04 Er 0.96 FeO3, (d) is Ce 0.06 Er 0.94 Microscopic morphology image (SEM) of FeO3;

[0031] Figure 3 Ce obtained by the present invention x Er 1-x Elemental surface distribution diagrams of FeO3 (x=0.00, 0.02, 0.04, 0.06), (a), (b), (c), and (d) represent Er, Fe, O, and Ce, respectively;

[0032] Figure 4 ErFeO3 and Ce (undoped Ce) 0.02 Er 0.98 FeO3, Ce 0.04 Er 0.96 FeO3, Ce0.06 Er 0.94 (a) Hysteresis loop diagram and (b) Local hysteresis loop diagram of FeO3;

[0033] Figure 5 ErFeO3 and Ce (undoped Ce) 0.02 Er 0.98 FeO3, Ce 0.04 Er 0.96 FeO3, Ce 0.06 Er 0.94 Magnetic loss tangent of FeO3;

[0034] Figure 6 ErFeO3 and Ce (undoped Ce) 0.02 Er 0.98 FeO3, Ce 0.04 Er 0.96 FeO3, Ce 0.06 Er 0.94 Dielectric loss tangent of FeO3;

[0035] Figure 7 Ce obtained by the present invention x Er 1-x Color changes of FeO3 after different degrees of mechanical grinding;

[0036] Figure 8 Ce obtained by the present invention x Er 1-x Particle size distribution of FeO3 without mechanical grinding;

[0037] Figure 9 Ce obtained by the present invention x Er 1-x Particle size distribution of FeO3 after light grinding;

[0038] Figure 10 Ce obtained by the present invention x Er 1-x Particle size distribution of FeO3 after heavy grinding. Detailed Implementation

[0039] Example 1

[0040] A method for preparing Ce-doped erbium ferrite material includes the following steps:

[0041] Step A: Weigh 14g of Fe2O3 powder, 32.9g of Er2O3 powder and 0.6g of CeO2 powder, and mix them to obtain a mixed powder;

[0042] Step B: The mixed powder obtained in Step A, 50g of zirconia balls with a diameter of 5mm, 50g of zirconia balls with a diameter of 1mm, and 150g of deionized water are ball-milled and mixed using a planetary ball mill. The process parameters are: rotation speed 250rpm, ball milling for 10 minutes, stop for 1-2 minutes, cycle 28 times (total effective ball milling time 280 minutes). After the ball-milled slurry is ultrasonically dispersed for 24 hours, a uniformly mixed slurry is obtained.

[0043] Step C: Dry the slurry obtained in step B in an oven at 80℃ for 8 hours to obtain a dry powder. Take 3g of the dry powder and press it into shape under a pressure of 10MPA, holding the pressure for 5-10 minutes to obtain a sheet-like blank.

[0044] Step D: Place the sheet-like billet in a muffle furnace and heat it from 50°C to 1500°C at a heating rate of 5°C / min in air atmosphere. Hold the temperature for 10 hours and then cool it to room temperature in the furnace to obtain Ce. 0.02 Er 0.98 FeO3 materials.

[0045] According to VSM testing, the Ce obtained in this embodiment 0.02 Er 0.98 The coercivity of FeO3 material is approximately 57.92% of that of undoped Ce ErFeO3, and the magnetic loss tangent tanδ is positive in the 2-10 GHz range. μ ≤0.0255.

[0046] Example 2

[0047] The difference from Example 1 is that 14g of Fe2O3 powder, 32.2g of Er2O3 powder, and 1.2g of CeO2 powder were weighed, while the rest of the preparation method was the same as in Example 1, to obtain Ce. 0.04 Er 0.96 The FeO3 material, as measured by VSM, exhibits a coercivity approximately 62.68% that of undoped Ce ErFeO3, and a magnetic loss tangent tanδ within the 2-10 GHz range. μ ≤0.0255.

[0048] Example 3

[0049] The difference from Example 1 is that 14g of Fe2O3 powder, 31.5g of Er2O3 powder, and 1.8g of CeO2 powder were weighed, while the rest of the preparation method was the same as in Example 1, to obtain Ce. 0.06 Er 0.94 The FeO3 material, as measured by VSM, exhibits a coercivity approximately 117.92% that of undoped Ce ErFeO3, and a magnetic loss tangent tanδ within the 2-10 GHz range. μ ≤0.0255.

[0050] Comparative Example 1

[0051] 14g of Fe₂O₃ powder and 34.8g of Er₂O₃ powder were weighed, and the remaining preparation methods were the same as in Example 1 to obtain undoped Ce ErFeO₃ material as a control sample. Testing showed that the undoped Ce ErFeO₃ had a high coercivity of approximately 2208.16 Oe; and a magnetic loss tangent tanδ in the 2-10 GHz range. μ ≤0.0255. The coercivity comparison between Examples 1-3 and Comparative Example 1 is shown in Table 1 below:

[0052] Table 1. Coercivity of Examples 1-3 and Comparative Example 1

[0053]

[0054] The Ce prepared above x Er 1-x FeO3 (x=0.00, 0.02, 0.04, 0.06) in its unground state is recorded as blocky, and Ce... x Er 1-x The yellow particles obtained after heavy mechanical grinding of FeO3 (0.02, 0.04, 0.06) are denoted as powder. Ce... x Er 1-x The intermediate local areas of FeO3 (x=0.00, 0.02, 0.04, 0.06) in its unground state are denoted as local microstructures. XRD tests were performed on the bulk, powder, and local microstructures, and the results are as follows: Figure 1 As shown, the XRD crystal structure of Ce-doped erbium ferrite material remains unchanged before and after mechanical grinding.

[0055] The undoped Ce ErFeO3 material prepared in Comparative Example 1 and the Ce materials prepared in Examples 1-3 were compared. 0.02 Er 0.98 FeO3, Ce 0.04 Er 0.96 FeO3, Ce 0.06 Er 0.94 FeO3 was characterized by SEM; the results are as follows: Figure 2 As shown, most grains exhibit a polygonal morphology with clear grain boundaries. The grain size gradually decreases with increasing Ce content, indicating that Ce doping effectively suppresses grain growth during high-temperature sintering. For Ce... 0.02 Er 0.98 In the FeO3 sample, layered precipitates appeared at the grain boundaries. This is due to the presence of Ce at lower doping levels. 3+ / Ce 4+Ions accumulate at grain boundaries, with local concentrations exceeding the solubility limit during sintering, leading to grain boundary migration and discontinuous grain growth. Figure 3 The elemental distribution map shows a relatively uniform elemental distribution. Through analysis of Ce... x Er 1-x SEM images of FeO3 ceramic samples: Ce 3+ / Ce 4+ Doping has a significant impact on the surface microstructure of ErFeO3. The average grain size of pristine ErFeO3 is relatively large. With increasing Ce doping concentration, grain growth is effectively suppressed, the proportion of coarse grains gradually decreases, and the grain refinement effect becomes increasingly apparent. Among all samples, Ce... 0.06 Er 0.94 FeO3 exhibits the smallest average grain size. This phenomenon can be attributed to part of Er 3+ Ce 3+ / Ce 4+ Ion substitution, in which some ions tend to segregate at grain boundaries, creates a solute drag effect, thereby hindering grain boundary migration and inhibiting grain growth. Furthermore, grain boundaries are typically regions where defects and space charge accumulate. Therefore, reducing grain size leads to an increase in grain boundary density, providing more active interfaces for interfacial polarization and space charge polarization, which in turn further affects the electromagnetic properties of the material.

[0056] The undoped Ce ErFeO3 material prepared in Comparative Example 1 and the Ce materials prepared in Examples 1-3 were compared. 0.02 Er 0.98 FeO3, Ce 0.04 Er 0.96 FeO3, Ce 0.06 Er 0.94 FeO3 was characterized for its properties, such as Figure 4 As shown, the hysteresis loops were measured at room temperature using VSM. All samples exhibited narrow hysteresis loops and no obvious magnetic saturation was observed within the measured magnetic field range, indicating typical tilted antiferromagnetic behavior. This characteristic is consistent with ErFeO3, where the weak ferromagnetic component originates from the spin tilt in the antiferromagnetically ordered Fe sublattice.

[0057] As shown in Table 1, the coercivity exhibits a non-monotonic change with increasing Ce doping concentration, initially decreasing and then increasing. The coercivity of undoped ErFeO3 is approximately 2208.16 Oe, decreasing to approximately 1279.02 Oe at (x = 0.02), and then increasing to nearly 2603.93 Oe at (x = 0.06). At low doping levels, the introduction of mixed-valence Ce ions may induce charge compensation, moderate oxygen vacancy formation, and local lattice distortion. These factors can alter the Fe-O-Fe bond angle and superexchange interaction, thereby reducing domain wall movement resistance and leading to a decrease in coercivity. With further increases in Ce content, the increased defect concentration and enhanced lattice distortion strengthen the domain wall fixation effect, causing the coercivity to rise accordingly. This demonstrates bidirectional tunability of the coercivity, optimizing the magnetic properties.

[0058] like Figure 5 , 6 As shown, the magnetic loss tangent tanδ of Ce-doped erbium ferrite and undoped ErFeO3 materials is... μ ≤0.0255, dielectric loss tangent tanδ 𝜀 The values ​​are all below 0.01, which is within a low range. This means that by adjusting the Ce doping amount, the coercivity can be bidirectionally controlled within a certain range to meet the different coercivity requirements of various magnetic storage devices, while maintaining high-frequency and low electromagnetic loss characteristics.

[0059] like Figure 7 As shown, the materials prepared in Examples 1-3 above are used as anti-counterfeiting marks. The marks are ground to produce three different colors: black, red, and yellow, in order to verify their authenticity.

[0060] The magnetic properties of Ce-doped erbium ferrite materials prepared by this invention at specific Ce doping levels (0.02≤x≤0.06) can be applied to magnetic storage devices, magnetic sensor devices, or spintronic devices.

[0061] The magnetic properties of Ce-doped erbium ferrite materials prepared by this invention at specific Ce doping levels (0.02≤x≤0.06) and the different particle sizes under different degrees of mechanical grinding can also be applied to the preparation of intelligent strain sensors, structural health monitoring systems, or mechanical stress visualization indicators.

[0062] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A Ce-doped erbium ferrite material, characterized in that, The general chemical formula for Ce-doped erbium ferrite materials is Ce x Er 1-x FeO3, where x takes values ​​in the range of 0.02≤x≤0.06; when 0.02≤x≤0.06, Ce-doped erbium ferrite material achieves a decrease in coercivity followed by an increase while maintaining high-frequency and low electromagnetic loss characteristics; and Ce-doped erbium ferrite material is black in its unground state, turns into red particles after light grinding in a grinding container; further heavy grinding of the red particles or the unground Ce-doped erbium ferrite material gradually turns them into yellow particles, while the XRD crystal structure of Ce-doped erbium ferrite material does not change before and after grinding.

2. The Ce-doped erbium ferrite material according to claim 1, characterized in that, Light grinding refers to grinding for 1 to 2 minutes, after which the median diameter of the red particles obtained is 50.08 ± 4.23 μm; Heavy grinding refers to grinding for 10 to 15 minutes, after which the median diameter of the yellow particles obtained is 11.52 ± 3.83 μm.

3. A method for preparing Ce-doped erbium ferrite material according to claim 1 or 2, characterized in that, Includes the following steps: Step A: Weigh out Fe2O3 powder, Er2O3 powder and CeO2 powder, and mix them to obtain a mixed powder; Step B: Ball mill the mixed powder, grinding media and solvent to obtain a uniformly mixed slurry; Step C: After drying the slurry obtained in step B, press it into shape to obtain a sheet-like blank; Step D: Place the sheet-like blank in a muffle furnace and sinter it in an air atmosphere. Cool it to room temperature with the furnace to obtain the Ce-doped erbium ferrite material as described in any one of claims 1 to 2.

4. The method for preparing Ce-doped erbium ferrite material according to claim 3, characterized in that, In step A, the molar ratio of Fe, Er, and Ce elements in Fe2O3 powder, Er2O3 powder, and CeO2 powder is 1:(1-x):x, where 0.02≤x≤0.

06.

5. The method for preparing Ce-doped erbium ferrite material according to claim 3, characterized in that, In step B, the mass ratio of the mixed powder, grinding media and solvent is 1:(1-3):(1-4), wherein the grinding media is zirconia balls and the solvent is water or ethanol; the ball milling speed is 200-400 rpm and the ball milling time is 5-10 hours.

6. The method for preparing Ce-doped erbium ferrite material according to claim 3, characterized in that, In step C, the drying temperature is 80-120℃, the drying time is 8-24 hours, and the pressing conditions are: pressure of 5-10 MPa and holding time of 5-10 minutes. In step D, the sintering conditions are: starting temperature 50℃, heating to 1450-1550℃ at a heating rate of 3-5℃ / min, and holding time of 10-14 hours.

7. An application of Ce-doped erbium ferrite material in anti-counterfeiting markings, characterized in that, Ce-doped erbium ferrite material prepared using any one of claims 1 to 2 or any one of claims 3 to 6.

8. The application of a Ce-doped erbium ferrite material in anti-counterfeiting markings according to claim 7, characterized in that, Anti-counterfeiting measures include the production of anti-counterfeiting labels, anti-counterfeiting inks, or anti-counterfeiting films.

9. An application of Ce-doped erbium ferrite material in the fabrication of intelligent strain sensors, structural health monitoring systems, or mechanical stress visualization indicators, characterized in that, Ce-doped erbium ferrite material prepared using the Ce-doped erbium ferrite material according to claim 1 or the preparation method of the Ce-doped erbium ferrite material according to any one of claims 2 to 6.

10. An application of Ce-doped erbium ferrite material in magnetic storage devices, magnetic sensor devices, or spintronic devices, characterized in that, The Ce-doped erbium ferrite material according to claim 1 or the Ce-doped erbium ferrite material prepared by any one of claims 2 to 6 is used as a magnetic storage material.

Images