阅读说明：本技术 低磁场域下高应变灵敏度的磁致伸缩材料及其制备方法 (Magnetostrictive material with high strain sensitivity in low magnetic field and preparation method thereof ) 是由 李元勋 王桂娟 陆永成 彭睿 苏桦 张仕俊 徐雷 于 2021-01-11 设计创作，主要内容包括：本发明属于电子材料技术领域,具体涉及一种低磁场域下高应变灵敏度的磁致伸缩材料及其制备方法。本发明在具有高磁致伸缩系数的钴铁氧体的基础上,首次采用Mg～(2+)和Zr～(4+)复合取代CoFe-2O-4,通过取代元素的选取以及配方比例选择,实现不同占位,其中Mg～(2+)倾向于同时占据四面体位点和八面体位点,Zr～(4+)倾向于取代四面体位点,在两个位点的共同取代的作用下实现了钴铁氧体在低磁场域下的3.3×10～(-9)A～(-1)m～4.3×10～(-9)A～(-1)m的应变灵敏度,极大的提升了当前低磁场域下钴铁氧体的应变灵敏度,使其具有更好的应用前景,从而为磁传感器在更低磁场下工作的可能提供了基础。(The invention belongs to the technical field of electronic materials, and particularly relates to a magnetostrictive material with high strain sensitivity in a low magnetic field and a preparation method thereof. The invention adopts Mg for the first time on the basis of the cobalt ferrite with high magnetostriction coefficient 2+ And Zr 4+ Compositely substituted CoFe 2 O 4 Realizing different occupation by selecting substitute elements and selecting formula proportion, wherein Mg 2+ Tending to occupy both tetrahedral and octahedral sites, Zr 4+ Tends to replace tetrahedral sites, and 3.3X 10 of cobalt ferrite in a low magnetic field domain is realized under the effect of the mutual substitution of two sites ‑9 A ‑1 m～4.3×10 ‑9 A ‑1 The strain sensitivity of m greatly improves the strain sensitivity of the cobalt ferrite in the current low magnetic field regionThe sensitivity is changed, so that the magnetic sensor has better application prospect, and a foundation is provided for the possibility that the magnetic sensor works under a lower magnetic field.)

1. A magnetostrictive material with high strain sensitivity in a low magnetic field is characterized in that:

the chemical general formula is CoMg_xZr_yFe_2-x-yO₄Wherein x is 0.025-0.05, and y is 0.02-0.06; strain sensitivity of 3.3X 10^-9A^-1m～4.3×10^-9A^-1m；

MgO is adopted: ZrO (ZrO)₂：Co₂O₃：Fe₂O₃Raw materials are mixed according to a molar ratio of MgO: ZrO (ZrO)₂：Co₂O₃：Fe₂O₃Is 0.05: 0.02-0.06: 0.5: 0.945 to 0.965 inclusive of ZrO₂With Fe₂O₃Is prepared by a solid phase method; the presintering temperature in the solid phase method is 1000-1100 ℃, and the sintering temperature is 1250-1300 ℃.

2. A magnetostrictive material with high strain sensitivity in the low magnetic field according to claim 1, characterized in that:

step 1, mixing raw materials of MgO: ZrO (ZrO)₂：Co₂O₃：Fe₂O₃Is 0.05: 0.02-0.06: 0.5: 0.945-0.965, wherein ZrO₂With Fe₂O₃The molar ratio of (a) to (b);

step 2, mixing the raw materials prepared in the step 1 according to the following materials: deionized water: the mass ratio of the ball is 1: 1: 1.2-1.5, the rotating speed of the ball mill is 250 r/min-300 r/min, the ball milling time is 6 h-8 h, the first ball milling is carried out, and then the ball is dried at 80-120 ℃ and passes through a screen mesh of 40-120 meshes;

step 3, pre-sintering the ball-milling powder obtained in the step 2 at 1000-1100 ℃, keeping the temperature for 2-3 h, and increasing the temperature at a rate of 1-2 ℃/min;

step 4, mixing the product obtained in the step 3 according to the following materials: deionized water: the mass ratio of the ball is 1: 1: 1.2-1.5, performing secondary ball milling at the ball mill rotation speed of 250-300 r/min for 8-10 h; then drying at 80-120 ℃, adding 2-5% of PVA solution as a binder for granulation after drying, and carrying out compression molding at 8-10 MPa for 30-60 s of pressure maintaining time;

step 5, sintering the sample obtained in the step 4 at 1250-1300 ℃, wherein the heating rate is 1-2 ℃/min, the heat preservation time is 4-6 h, and the magnetostrictive material CoMg with high strain sensitivity in a low magnetic field region can be obtained after the sample is naturally cooled_xZr_yFe_2-x-yO₄。

3. A magnetostrictive material with high strain sensitivity in the low magnetic field according to claim 1, characterized in that: and 5, after sintering, a cooling process is carried out, and the mixture is cooled to 700 ℃ at a cooling rate of 1-2 ℃/min and then is naturally cooled.

Technical Field

The invention belongs to the technical field of electronic materials, and particularly relates to a magnetostrictive material with high strain sensitivity in a low magnetic field and a preparation method thereof.

Background

Magnetostrictive materials are widely used in magnetostrictive sensors and actuators, linear motors, vibration and noise control, mechanical torque sensors, ultrasonic generators, and the like.

Rare earth-based magnetostrictive material (Terfenol-D) is widely used, but is gradually replaced by Ga-Fe alloy (Galfenol) and derivatives thereof due to the fact that the Terfenol-D is easy to corrode and expensive. Although the Galfenol-based material has good magnetostrictive performance under a low magnetic field, the Galfenol-based material has low resistivity and generates high eddy current loss when being applied under medium and low frequencies, so that the application range of the Galfenol-based material is greatly limited.

CoFe₂O₄Has the characteristics of remarkable magnetostriction performance and high resistivity in both single crystal (lambda-600 ppm) and polycrystal (lambda-150-400 ppm), thereby being researched to be used as a magnetostriction component in a multiferroic electric composite material to realize better magnetoelectric coefficient (alpha)_ME) And further applied to magnetic field sensors, wireless power supply systems, double electric fields and magnetic field adjustable devices and the like. But CoFe₂O₄Strain sensitivity [ d λ/dH ] in low magnetic field region]Lower, and further improvements in strain sensitivity are still needed to further expand the range of applications.

Not only does it aim at cobalt ferrite as a mixed spinel ferriteModification studies were carried out on sensitivity of change, for example, Vinitha Reddy Monaji et al prepared Co by solid phase synthesis_1+xZr_xFe_2-2xO₄Discovery of Zr⁴⁺Tends to replace tetrahedral Fe³⁺The strain sensitivity is improved to 3.32 multiplied by 10^-9A^-1And m is selected. P.n.anantharamaiah and p.a.joy synthesized CoMg_xFe_2-xO₄(0-0.2) Mg was found²⁺For Fe of tetrahedral site and octahedral site³⁺All have a tendency to substitute, their CoMg_xFe_2-xO₄There was some improvement in strain sensitivity at low magnetic fields, with the sample having the best strain sensitivity (2.05 × 10) for x ═ 0.05^-9A^-1m). Although Mg is present²⁺And Zr⁴⁺Substituted pair CoFe₂O₄The strain sensitivity of (a) is improved to a certain extent, but the improvement is limited, and the problem of poor strain sensitivity in a low magnetic field region is still not well solved.

Disclosure of Invention

Aiming at the problems or the defects, the invention provides a magnetostrictive material with high strain sensitivity in a low magnetic field and a preparation method thereof, aiming at solving the problem that the strain sensitivity of the existing cobalt ferrite as the magnetostrictive material is poor in the low magnetic field.

A magnetostrictive material with high strain sensitivity in low magnetic field is prepared from Co ferrite and Mg²⁺And Zr⁴⁺By substitution of Fe in different positions³⁺The chemical formula is CoMg_xZr_yFe_2-x-yO₄Wherein x is 0.025-0.05, and y is 0.02-0.06; strain sensitivity of 3.3X 10^-9A^-1m～4.3×10^-9A^-1And m is selected. MgO is adopted: ZrO (ZrO)₂：Co₂O₃：Fe₂O₃Raw materials are mixed according to a molar ratio of MgO: ZrO (ZrO)₂：Co₂O₃：Fe₂O₃Is 0.05: 0.02-0.06: 0.5: 0.945 to 0.965 inclusive of ZrO₂With Fe₂O₃The molar ratio of (A) to (B)Prepared by a solid phase method; the presintering temperature in the solid phase method is 1000-1100 ℃, and the sintering temperature is 1250-1300 ℃.

The preparation method of the magnetostrictive material with high strain sensitivity in the low magnetic field comprises the following steps:

step 1, mixing raw materials of MgO: ZrO (ZrO)₂：Co₂O₃：Fe₂O₃Is 0.05: 0.02-0.06: 0.5: 0.945 to 0.965 inclusive of ZrO₂With Fe₂O₃The molar ratio of the component (a) to (b) is reduced, and the mixture is prepared for later use.

Step 2, mixing the raw materials prepared in the step 1 according to the following materials: deionized water: the mass ratio of the ball is 1: 1: 1.2-1.5, the rotating speed of the ball mill is 250 r/min-300 r/min, the ball milling time is 6 h-8 h, the first ball milling is carried out, and then the ball is dried at 80-120 ℃ and passes through a screen mesh of 40-120 meshes.

And 3, pre-sintering the ball-milling powder obtained in the step 2 at 1000-1100 ℃, keeping the temperature for 2-3 h, and increasing the temperature at the rate of 1-2 ℃/min.

Step 4, mixing the product obtained in the step 3 according to the following materials: deionized water: the mass ratio of the ball is 1: 1: 1.2-1.5, performing secondary ball milling at the ball mill rotation speed of 250-300 r/min for 8-10 h; and then drying at 80-120 ℃, adding 2-5% by mass of PVA solution as a binder for granulation after drying, and performing compression molding at 8-10 MPa for 30-60 s of pressure maintaining time.

Step 5, sintering the sample obtained in the step 4 at 1250-1300 ℃, wherein the heating rate is 1-2 ℃/min, the heat preservation time is 4-6 h, and the magnetostrictive material CoMg with high strain sensitivity in a low magnetic field region can be obtained after the sample is naturally cooled_xZr_yFe_2-x-yO₄。

The invention adopts Mg for the first time on the basis of the cobalt ferrite with high magnetostriction coefficient²⁺And Zr⁴⁺Compositely substituted CoFe₂O₄Realizing different occupation by selecting substitute elements and selecting formula proportion, wherein Mg²⁺Tending to occupy both tetrahedral and octahedral sites, Zr⁴⁺Tend to replace fourThe surface body site realizes 3.3 multiplied by 10 of cobalt ferrite in a low magnetic field domain under the action of the common substitution of the two sites^-9A^-1m～4.3×10^-9A^-1The strain sensitivity of m greatly improves the strain sensitivity of the cobalt ferrite in the current low magnetic field area, so that the cobalt ferrite has better application prospect.

In conclusion, the invention improves the strain sensitivity of the magnetostrictive material in a low magnetic field area, thereby providing a foundation for the possibility that the magnetic sensor works in a lower magnetic field.

Drawings

FIG. 1 is a flow chart of a process for preparing a material by a solid-phase reaction method;

fig. 2 shows Fe in cobalt ferrites reported by p.n.anantharamaiah and p.a.joy³⁺Is coated with Mg²⁺Strain sensitivity of the substituted sample;

FIG. 3 shows Fe in cobalt ferrite reported by Vinitha Reddy Monaji et al³⁺Quilt Zr⁴⁺Strain sensitivity of the substituted sample;

FIG. 4 shows Fe in cobalt ferrite of example³⁺Is coated with Mg²⁺And Zr⁴⁺Strain sensitivity of the simultaneously substituted samples, where y denotes Zr⁴⁺In a molar ratio of (a).

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Example 1:

(1) the following raw material components and content thereof are adopted to prepare a material CoMg_0.05Zr_0.02Fe_1.93O₄：

Table 1: EXAMPLE 1 formulation Table (unit: mol)

MgO	ZrO2	Co2O3	Fe2O3
				0.05	0.02	0.5	0.965

(2) Weighing raw materials according to the formula proportion of the formula shown in the table 1, performing ball-milling mixing, drying, crushing and sieving, pre-sintering, granulating, molding and sintering on the raw materials to obtain the material with high strain sensitivity in a low magnetic field region, wherein the pre-sintering temperature is 1100 ℃, the molding pressure is 10MPa, the pressure maintaining time is 30s, the sintering temperature is 1300 ℃, the heating rate and the cooling rate are 2 ℃/min, the heat preservation time is 4h, and the material is naturally cooled after the temperature is reduced to 700 ℃.

Example 2:

(1) the following raw material components and content thereof are adopted to prepare a material CoMg_0.05Zr_0.04Fe_1.91O₄：

Table 2: EXAMPLE 2 formulation Table (unit: mol)

MgO	ZrO2	Co2O3	Fe2O3
				0.05	0.04	0.5	0.955

(2) Weighing the raw materials according to the formula proportion of the formula shown in the table 2, performing ball-milling mixing, drying, crushing and sieving, pre-sintering, granulating, molding and sintering on the raw materials to obtain the material with high strain sensitivity in a low magnetic field region, wherein the pre-sintering temperature is 1100 ℃, the molding pressure is 10MPa, the pressure maintaining time is 30s, the sintering temperature is 1300 ℃, the heating rate and the cooling rate are 2 ℃/min, the heat preservation time is 4h, and the material is naturally cooled after the temperature is reduced to 700 ℃.

Example 3:

(1) the following raw material components and content thereof are adopted to prepare a material CoMg_0.05Zr_0.06Fe_1.89O₄：

Table 3: EXAMPLE 3 recipe Table (unit: mol)

MgO	ZrO2	Co2O3	Fe2O3
				0.05	0.06	0.5	0.945

(2) Weighing the raw materials according to the formula proportion in the table 3, performing ball-milling mixing, drying, crushing and sieving, pre-sintering, granulating, molding and sintering on the raw materials to obtain the material with high strain sensitivity in a low magnetic field region, wherein the pre-sintering temperature is 1100 ℃, the molding pressure is 10MPa, the pressure maintaining time is 30s, the sintering temperature is 1300 ℃, the heating rate and the cooling rate are 2 ℃/min, the heat preservation time is 4h, and the material is naturally cooled after the temperature is reduced to 700 ℃.

The materials prepared in the above 3 examples were tested and the results are shown in fig. 4. As can be seen from FIG. 4, for Mg²⁺And Zr⁴⁺Compositely substituted CoFe₂O₄Different proportions can greatly improve the strain sensitivity of the cobalt ferrite in a low magnetic field region (3.3 multiplied by 10)^-9A^-1m～4.3×10^-9A^-1m) provides the basis for the possibility of magnetic sensors operating at lower magnetic fields.

In conclusion, the invention adopts Mg for the first time on the basis of the cobalt ferrite with high magnetostriction coefficient²⁺And Zr⁴⁺Compositely substituted CoFe₂O₄Realizing different occupation by selecting substitute elements and selecting formula proportion, wherein Mg²⁺Tending to occupy both tetrahedral and octahedral sites, Zr⁴⁺Tends to replace tetrahedral sites, and 3.3X 10 of cobalt ferrite in a low magnetic field domain is realized under the effect of the mutual substitution of two sites^-9A^-1m～4.3×10^-9A^-1The strain sensitivity of m greatly improves the strain sensitivity of the cobalt ferrite in the current low magnetic field area, so that the cobalt ferrite has better application prospect.