阅读说明：本技术 一种Ga系MAX相磁性材料及其制备方法和应用 (Ga series MAX phase magnetic material and preparation method and application thereof ) 是由 宋礼 王昌达 郭鑫 魏世强 于 2021-08-19 设计创作，主要内容包括：本发明属于纳米新材料技术领域,本发明提供了一种Ga系MAX相磁性材料及其制备方法和应用,所述Ga系MAX相磁性材料的分子式表示为M-(2)(Ga-(1-x)Z-(x))-(2)X,M为Mo、Ti、Nb、Ta、V、Cr元素中的任意一种,Z为磁性金属元素,0<x<1,X为C、N的任意一种或组合；所述Ga系MAX相磁性材料具有双Ga层分隔MX层的层状结构。本发明提供的MAX相磁性材料的相结构稳定,具有较好的磁学性能,在电化学催化、储能、吸波或自旋电子器件中具有潜在应用价值。所述Ga系MAX相磁性材料的制备方法以M-(2)Ga-(2)CMAX为原料,通过磁性元素与MAX层间的Ga元素置换反应获得该Ga系磁性材料,方法简单、可调控。(The invention belongs to the technical field of new nano-materials, and provides a Ga-series MAX-phase magnetic material, and a preparation method and application thereof, wherein the molecular formula of the Ga-series MAX-phase magnetic material is expressed as M 2 (Ga 1‑x Z x ) 2 X and M are any one of Mo, Ti, Nb, Ta, V and Cr, Z is a magnetic metal element, 0<x<1, X is C, N; the Ga-based MAX phase magnetic material has a layered structure with double Ga layers separating MX layers. The MAX phase magnetic material provided by the invention has a stable phase structure, has good magnetic properties, and has potential application value in electrochemical catalysis, energy storage, wave absorption or spin electronic devices. The preparation method of the Ga series MAX phase magnetic material uses M 2 Ga 2 CMAX is used as raw material, and Ga between the magnetic element and MAX layer is substitutedThe method is simple and controllable to obtain the Ga-based magnetic material.)

1. A Ga-series MAX-phase magnetic material is characterized in that the molecular formula is M₂(Ga_1-xZ_x)₂X, wherein M is any one of Mo, Ti, Nb, Ta, V and Cr, Z is a magnetic metal element, 0<x<1, X is C, N;

the Ga-based MAX phase magnetic material has a layered structure with double Ga layers separating MX layers.

2. The Ga-based MAX phase magnetic material according to claim 1, wherein Z is one or a combination of two or more selected from Mn, Fe, Co and Ni.

3. The Ga-based MAX phase magnetic material according to claim 1 or 2, wherein X is C or C_aN_bWherein a + b is 1.

4. A method for producing a Ga-based MAX phase magnetic material according to any one of claims 1 to 3, comprising:

using a molecular formula of M₂Ga₂MAX nanomaterial of X, and divalentPerforming a replacement reaction on the A site of the MAX phase by using a magnetic metal source substance to obtain a Ga system MAX phase magnetic material;

wherein M is any one of Mo, Ti, Nb, Ta, V and Cr elements, and X is any one or combination of C, N.

5. The preparation method according to claim 4, comprising the following steps:

s1) molecular formula M₂Ga₂Grinding and mixing MAX nano powder of X, divalent magnetic metal salt and monovalent inorganic salt to obtain a mixture;

s2) placing the mixture obtained in the step S1) in an inert atmosphere for high-temperature replacement reaction, and soaking the obtained reaction product in an acid solution to obtain the Ga system MAX phase magnetic material.

6. The method according to claim 5, wherein the divalent magnetic metal salt of S1) is selected from MnCl₂、FeCl₂、CoCl₂、NiCl₂And hydrates thereof, or a combination of two or more thereof.

7. The method according to claim 5, wherein the monovalent inorganic salt in S1) is Na salt and/or K salt, and comprises one or a combination of two or more of NaF, KF, NaCl, KCl, NaBr, KBr, NaI and KI.

8. The method according to claim 5, wherein the molar ratio of MAX nanopowder to divalent magnetic metal salt in S1) is less than or equal to 1: 4; the molar ratio of MAX nanopowder to monovalent inorganic salt is 1: (0-3).

9. The preparation method according to claim 5, wherein the temperature of the high-temperature displacement reaction in S2) is 400-700 ℃; the time of the high-temperature replacement reaction is 0.5-12 h.

10. Use of a Ga-based MAX phase magnetic material according to any of claims 1 to 3 for the preparation of electrochemical catalytic, energy storing, wave absorbing or spintronic devices.

Technical Field

The invention belongs to the technical field of new nano-materials, and particularly relates to a Ga-series MAX-phase magnetic material and a preparation method and application thereof.

Background

MAX phase materials are general names of ternary layered cermet materials, and the compounds have a uniform chemical formula M_n+1AX_n(n is 1, 2 or 3),m represents an early transition metal element such as Ti, V, Mo, etc.; a is mainly an element of group 13 or 14, such as Al, Ga, Si, etc.; x represents C and/or N. Unit cell of MAX phase material is composed of M_n+1X_nThe unit and the A atomic surface are alternately stacked to form a close-packed hexagonal layered structure, the unit has the characteristics of metal and ceramic, and shows excellent physical, chemical, mechanical, electrical and other properties. In recent years, scientists have been theoretically predicting and synthesizing new MAX phase materials, and further extending the composition and properties of the MAX phase by doping, solid solution or substitution. Among them, magnetic properties are a promising direction, and in a nano-layered magnetic material, a giant magnetoresistance phenomenon occurs by exchange coupling between magnetic multilayer films, which makes the material have great potential applications in the fields of data storage, magnetic recording, electron spin, and the like. Therefore, the synthesis and application of magnetic MAX phase functional materials will be the focus and focus of future MAX phase material research.

It has been found that a magnetic MAX phase material with one or more magnetic elements (Mn, Fe, Co, Ni) occupying the a site can be prepared by alloying, substitution, etc. Such MAX phase materials have a single a layer, and magnetism is generated by in-plane electron exchange coupling of a magnetic element and an a-bit element, but the introduction of the magnetic element increases the disorder of the material at the same time, so that the stability of the MAX phase structure is reduced, and the application is affected.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a Ga series MAX phase magnetic material and a preparation method and application thereof.

The present invention provides a Ga-based MAX phase magnetic material with a molecular formula of M₂(Ga_1-xZ_x)₂X, wherein M is any one of Mo, Ti, Nb, Ta, V and Cr, Z is a magnetic metal element, 0<x<1, X is C, N;

the Ga-based MAX phase magnetic material has a layered structure with double Ga layers separating MX layers.

Preferably, Z is selected from one or a combination of more than two of Mn, Fe, Co and Ni.

Preferably, X is C or C_aN_bWherein a + b is 1.

The general formula of the Ga series MAX phase magnetic material provided by the invention is as follows: m₂(Ga_1-xZ_x)₂X, a bulk Ga-based MAX phase layered structure, a magnetic metal element Z being solid-solved at the A site_x(0<x<1) And exhibits ferromagnetic properties. In the invention, the Ga system MAX phase magnetic material has the structural characteristic that double Ga layers separate MX layers, and besides single in-plane coupling, the Ga system MAX phase magnetic material also can additionally provide out-of-plane spin electronic coupling between A layers, thereby reducing the chemical disorder of magnetic elements and further improving the magnetic performance of MAX phase. At present, the double A-layer MAX phase magnetic material is only reported. The synthesis and discovery of the Ga system double A layer MAX phase magnetic material have important significance in the aspects of expanding MAX phase material family members, regulating and controlling the physical and chemical properties of MAX phase materials and the like.

The embodiment of the invention provides a preparation method of the Ga system MAX phase magnetic material, which comprises the following steps:

using a molecular formula of M₂Ga₂Carrying out a displacement reaction on the MAX nano material of X and a divalent magnetic metal source substance at the A position of the MAX phase to obtain a Ga series MAX phase magnetic material;

wherein M is any one of Mo, Ti, Nb, Ta, V and Cr elements, and X is any one or combination of C, N.

Preferably, the preparation method of the Ga-based MAX-phase magnetic material specifically includes the following steps:

s1) molecular formula M₂Ga₂Grinding and mixing MAX nano powder of X, divalent magnetic metal salt and monovalent inorganic salt to obtain a mixture;

s2) placing the mixture obtained in the step S1) in an inert atmosphere for high-temperature replacement reaction, and soaking the obtained reaction product in an acid solution to obtain the Ga system MAX phase magnetic material.

Preferably, the divalent magnetic metal salt in S1) is selected from MnCl₂、FeCl₂、CoCl₂、NiCl₂And hydrates thereof, and one or more than two of the hydratesAnd (4) combining.

Preferably, the monovalent inorganic salt in S1) is a Na salt and/or a K salt, including one or a combination of two or more of NaF, KF, NaCl, KCl, NaBr, KBr, NaI, and KI.

Preferably, the mole ratio of the MAX nanopowder to the divalent magnetic metal salt in S1) is less than or equal to 1: 4; the molar ratio of MAX nanopowder to monovalent inorganic salt is 1: (0-3).

Preferably, the temperature of the high-temperature replacement reaction in S2) is 400-700 ℃; the time of the high-temperature replacement reaction is 0.5-12 h.

In addition, the invention also provides application of the Ga system MAX phase magnetic material in preparation of electrochemical catalysis, energy storage, wave absorption or spinning electronic devices.

Compared with the prior art, the embodiment of the invention preferably utilizes a molten salt method to replace M by the divalent magnetic metal salt₂Ga₂Ga (gallium) in X dissolves a magnetic element in the A site of the Ga-based MAX phase, thereby further improving the magnetic properties of the MAX phase. The optimal preparation method is simple and controllable, the required synthesis temperature is low, the time is short, and the method has important significance in expanding the family members of the MAX phase material, regulating and controlling the physical and chemical properties of the MAX phase material and the like. The magnetic MAX phase material prepared by the embodiment of the invention has application prospects in multiple fields of electrochemical catalysis, energy storage, wave absorption or spin electronic devices and the like.

Drawings

FIG. 1 shows Ga-based Mo₂Ga₂ZFC and FC plots for cmax material;

FIG. 2 shows Mo₂Ga₂M-H plot of C at 2K;

FIG. 3 shows a Ga-based magnetic material Mo obtained in example 1 of the present invention₂(Ga_1-xFe_x)₂C and Mo₂Ga₂XRD pattern of C;

FIG. 4 shows a Ga-based magnetic material Mo obtained in example 1 of the present invention₂(Ga_1-xFe_x)₂SEM picture of C;

FIG. 5 shows a Ga-based magnetic material Mo obtained in example 1 of the present invention₂(Ga_1-xFe_x)₂SEM EDS for C;

FIG. 6 shows a Ga-based magnetic material Mo obtained in example 1 of the present invention₂(Ga_1-xFe_x)₂SEM Mapping chart of C;

FIG. 7 shows a Ga-based magnetic material Mo obtained in example 1 of the present invention₂(Ga_1-xFe_x)₂A TEM image of C;

FIG. 8 shows a Ga-based magnetic material Mo obtained in example 1 of the present invention₂(Ga_1-xFe_x)₂ZFC and FC plots of C;

FIG. 9 shows a Ga-based magnetic material Mo obtained in example 1 of the present invention₂(Ga_1-xFe_x)₂M-H plot of C at 2K;

FIG. 10 shows a Ga-based magnetic material Mo obtained in example 2 of the present invention₂(Ga_1-xNi_x)₂SEM Mapping chart of C;

FIG. 11 shows a Ga-based magnetic material Mo obtained in example 3 of the present invention₂(Ga_1-x1-x2Fe_x1Ni_x2)₂SEM Mapping chart of C;

FIG. 12 shows a Ga-based magnetic material Nb obtained in example 4 of the present invention₂(Ga_1-xFe_x)₂SEM Mapping chart of C;

FIG. 13 shows a Ga-based magnetic material Mo obtained in comparative example 1 of the present invention₂(Ga_1-xFe_x)₂SEM picture of C;

FIG. 14 shows a Ga-based magnetic material Mo obtained in comparative example 1 of the present invention₂(Ga_1-xFe_x)₂XRD pattern of C.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a Ga series MAX phase magnetic material, the molecular formula of which is M₂(Ga_1-xZ_x)₂X, wherein M is any one of Mo, Ti, Nb, Ta, V and Cr, Z is a magnetic metal element, 0<x<1, X is C, N;

the Ga-based MAX phase magnetic material has a layered structure with double Ga layers separating MX layers.

The MAX phase magnetic material provided by the invention has high phase structure stability and good magnetic performance, and is beneficial to application in electrochemical catalysis, energy storage, wave absorption or spin electronic devices.

The magnetic MAX phase material provided by the invention is a Ga system or Ga-based MAX phase magnetic material, and the molecular formula of the magnetic MAX phase material is expressed as M₂(Ga_1-xZ_x)₂And (4) X. Wherein, M is any one of molybdenum (Mo), titanium (Ti), niobium (Nb), tantalum (Ta), vanadium (V) and chromium (Cr), and can be specifically Mo or Nb. Z is preferably one or more magnetic elements of manganese (Mn), iron (Fe), cobalt (Co), and nickel (Ni), more preferably Fe and/or Ni; x represents an atomic weight ratio of 0<x<1, e.g. some M₂(Ga_1-xZ_x)₂In the X material, the atomic ratio of Mo, Ga and Fe is equal to or about equal to 2:1.55:0.45, and X represents the atomic stoichiometric ratio of Fe and Ga. In the molecular formula, X is any one or combination of carbon (C) and nitrogen (N); in some embodiments, X is C, and in other embodiments, X is C_aN_bWherein a + b is 1.

According to a specific example of the present invention, the Ga-based MAX phase magnetic material may be Mo₂(Ga_1-xFe_x)₂C material, Mo₂(Ga_1-xNi_x)₂C material, Mo₂(Ga_1-x1-x2Fe_x1Ni_x2)₂C material, Nb₂(Ga_1-xFe_x)₂C material, etc. x1 and x2 represent atomic weight ratio, 0<x1、x2<1。

The Ga system MAX phase magnetic material has a MAX phase layered structure and a nanosheet shape; and a magnetic metal element Z is solid-solved at the A position of the Ga-based MAX phase, and has ferromagnetic properties. In the invention, the Ga-based MAX phase magnetic material has the structural characteristic that double Ga layers separate MX layers (the double Ga layers can also be called as double A layers), and besides single in-plane coupling, out-of-plane spin electronic coupling between the A layers is additionally provided, so that the chemical disorder of magnetic elements is reduced, the phase structure is favorably stabilized, and the like, and the magnetic performance of the MAX phase can be further improved.

The Ga system double A layer MAX phase magnetic material is a new nano material, and has important significance in expanding MAX phase material family members, regulating and controlling MAX phase material physical and chemical properties and the like.

The embodiment of the invention provides a preparation method of the Ga system MAX phase magnetic material, which comprises the following steps: using a molecular formula of M₂Ga₂Carrying out a displacement reaction on the MAX nano material of X and a divalent magnetic metal source substance at the A position of the MAX phase to obtain a Ga series MAX phase magnetic material; wherein M is any one of Mo, Ti, Nb, Ta, V and Cr elements, and X is any one or combination of C, N.

Specifically, the preparation method of the Ga-based MAX phase magnetic material comprises the following steps:

s1) molecular formula M₂Ga₂Grinding and mixing MAX nano powder of X, divalent magnetic metal salt and monovalent inorganic salt to obtain a mixture;

s2) placing the mixture obtained in the step S1) in an inert atmosphere for high-temperature replacement reaction, and soaking the obtained reaction product in an acid solution to obtain the Ga system MAX phase magnetic material.

Preferably, the preparation method comprises the following steps: s1) firstly, M is added₂Ga₂Mixing the X MAX nano powder and divalent Z salt according to a certain molar ratio, and uniformly grinding to obtain a primary mixture; grinding and mixing the primary mixture and monovalent inorganic salt according to a molar ratio to obtain a final mixture; s2) carrying out high-temperature replacement reaction on the final mixture obtained in the step S1) in an inert atmosphere, and soaking the reaction product in an acid solution to obtain the Ga series MAX phase magnetic material M₂(Ga_1-xZ_x)₂X。

The present invention is not particularly limited in terms of the source of all raw materials, and may be commercially available.

In a preferred embodiment of the invention, M is used₂Ga₂C MAX is taken as a raw material, and firstly MnCl is included₂、FeCl₂、CoCl₂、NiCl₂And one or more than two divalent Z salts in the hydrates thereof are mixed according to a certain molar ratio, then are uniformly mixed with monovalent inorganic Na salt and/or K salt, are annealed in an inert atmosphere, and are subjected to a Ga element replacement reaction between the magnetic element Z and the MAX layers, so that the Ga-based magnetic material is obtained.

Wherein, M is₂Ga₂The X MAX nanopowder is a MAX phase nanomaterial, which is preferably Mo₂Ga₂X, more preferably Mo₂Ga₂And C, the preparation is simple and feasible. For the conventional requirements of raw materials, the plane shape has the area size of 2-10 microns and the longitudinal dimension of about 200-800 nm. The divalent Z salt is a divalent magnetic metal salt, preferably chloride MnCl₂、FeCl₂、CoCl₂、NiCl₂And hydrates thereof, and more preferably anhydrous compounds. The monovalent inorganic salt is preferably Na salt and/or K salt, including one or a combination of more than two of NaF, KF, NaCl, KCl, NaBr, KBr, NaI and KI, and is more preferably NaCl and KCl.

Said M₂Ga₂The molar ratio of xmax nanopowder to divalent Z salt is preferably less than or equal to 1: 4, for example, 1:5 to 6; the M is₂Ga₂The molar ratio of the xmax nanopowder to the monovalent inorganic salt may be 1: (0-3), the mole ratio of the MAX nanopowder to the NaCl and the KCl in the embodiment of the invention is preferably 1: 2: 2; the total grinding time is preferably 15min to 30 min. The embodiment of the invention also can not adopt an inorganic salt medium, and the main function of the inorganic salt is to reduce the melting point and prevent the phase change of MAX at high temperature and the generation of other side reactions in the preparation process; the preparation can also be carried out by directly heating without adding inorganic salt medium.

In the specific embodiment of the invention, the obtained final mixture is put into a ceramic ark and subjected to high-temperature replacement reaction in an inert atmosphere, namely high-temperature annealing to replace the magnetic element with the Ga element between MAX layers. In the present invention, the inert atmospherePreferably argon (Ar gas), and the temperature of the high-temperature replacement reaction is preferably 400-700 ℃ (the upper temperature limit is preferably lower than 700 ℃), and more preferably 450-650 ℃; the time of the high-temperature replacement reaction is preferably 0.5 to 12 hours, and more preferably 1 to 11 hours; the heating rate of the high-temperature displacement reaction is preferably 4-8 ℃/min, and more preferably 5 ℃/min. Under certain high-temperature reaction conditions, the material is easily oxidized due to overhigh temperature, so that anhydrous ferric chloride is converted into oxides such as ferric oxide, ferroferric oxide and the like, and the oxides have certain magnetism; in addition, some examples of the application prepare a double A layer M with Fe element for regulating and controlling magnetism₂Ga₂And X MAX, so that the experimental conditions are regulated and controlled within the range to avoid the generation of impurities.

After the high-temperature replacement reaction is finished, the embodiment of the invention preferably naturally cools to room temperature, and then the obtained product is placed in an acid solution for soaking treatment, mainly for removing metal oxides and metal clusters; and then, washing the magnetic material to be neutral by using deionized water and absolute ethyl alcohol, and freeze-drying to obtain the Ga system MAX phase magnetic material.

Wherein, the acid solution comprises sulfuric acid, hydrochloric acid and nitric acid with different concentrations, preferably hydrochloric acid; the concentration of the hydrochloric acid is preferably 6-12 mol/L, and the ratio of the total mass of the product to the acid solution is preferably 1 g: 20 mL; the soaking time can be 1 day to 3 days, preferably 2 days, and the soaking temperature is generally 15 ℃ to 30 ℃, preferably 25 ℃. Then preferably washing to neutrality, and cooling and drying to obtain the Ga system MAX phase magnetic material; the water washing preferably comprises washing the product with deionized water and absolute ethyl alcohol, and the freeze drying temperature is preferably-70 ℃ to-80 ℃; the vacuum degree of the freeze drying is preferably 5 Pa; the freeze-drying time is preferably 10 to 16 hours.

The preparation method of the Ga system MAX phase magnetic material is simple, the required synthesis temperature is low, and the time is short. The preparation method is adjustable and controllable, and improves the application prospect of the magnetic MAX phase material in multiple fields of electrochemical catalysis, energy storage, wave absorption or spin electronic devices and the like. The invention also provides application of the Ga system MAX phase magnetic material in preparation of electrochemical catalysis, energy storage, wave absorption or spinning electronic devices, and the Ga system MAX phase magnetic material has potential application value.

For further understanding of the present application, the Ga-based MAX-phase magnetic material provided herein, and the preparation method and application thereof are specifically described below with reference to examples. It should be understood, however, that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention, which is defined by the following examples.

The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by manufacturers, and are all conventional products available on the market.

Example 1

Weighing Mo according to the molar ratio of 1:5:2:2₂Ga₂C nanopowder, FeCl₂NaCl and KCl, first Mo₂Ga₂C and FeCl₂Putting into a mortar, grinding for 15min until the mixture is uniformly mixed, adding NaCl and KCl into the mortar, and fully grinding for 10min to obtain a mixed material.

Placing the mixed material in a ceramic square boat, placing in a high-temperature tube furnace, introducing Ar gas at the flow rate of 5sccm, heating to 120 ℃ at the heating rate of 5 ℃/min, maintaining for 30min, heating to 500 ℃ at the heating rate of 5 ℃/min, preserving heat for 8h, naturally cooling to room temperature, and taking out the ceramic square boat.

The product in the ceramic ark was taken out and put into a 50 ml beaker, and 20ml of concentrated hydrochloric acid was slowly dropped and left to stand at 25 ℃ for reaction for 48 hours, to remove the metal oxide and the Fe cluster. Washing with deionized water and absolute ethyl alcohol for multiple times until the pH value is 7, and then drying for 12 hours at the temperature of 80 ℃ below zero and the vacuum degree of 5 Pa to obtain the Ga magnetic material Mo₂(Ga_1-xFe_x)₂C。

FIG. 1 shows Ga-based Mo₂Ga₂ZFC and FC plots for cmax material; FIG. 2 shows Mo₂Ga₂M-H curve of C at 2K, materialExhibits antiferromagnetic properties at very low temperatures (2K) and is paramagnetic at room temperature.

X-ray diffraction technique on Mo obtained in example 1₂(Ga_1-xFe_x)₂C material and Mo₂Ga₂C, analyzing, and obtaining an X-ray diffraction pattern in figure 3. As can be seen from FIG. 3, after the magnetic elements are dissolved in the solution at the A site, Mo is located at 34.1 °, 37.3 ° and 42.5 ° positions₂Ga₂The characteristic peak of C is obviously reduced, and the characteristic peaks at the positions of 9.8 degrees and 39.9 degrees are obviously increased, but the positions of the characteristic peaks are almost unchanged, which shows that Mo is not changed by a solid solution magnetic element at the A position₂Ga₂A bulk layer structure of a cmax material.

The Mo obtained in example 1 was subjected to scanning electron microscopy, X-ray energy dispersion spectroscopy, or the like₂(Ga_1-xFe_x)₂Analyzing the material C to obtain a scanning electron microscope image, an SEM EDS image, an SEM Mapping image and a TEM image of the material C, and respectively showing in figures 4, 5, 6 and 7, wherein it can be seen that the appearance of the material is not greatly affected by Fe dissolved at the A position, and the MAX phase still shows a layered structure; fe element mainly occupies the A position, so that the molar ratio of Ga is reduced, the ratio of Mo to Ga to Fe is approximately equal to 2:1.55:0.45, the equal atomic weight Ga is replaced by the equal atomic weight Fe, and the Fe element is uniformly distributed in Mo₂Ga₂On the C nano-chip, Mo is relatively intuitively proved₂(Ga_1-xFe_x)₂And C, successfully preparing the material.

The Fe content was quantitatively measured by ICP, approximately between x-0.4-0.5, where x is the displacement saturation value.

FIG. 1 and FIG. 8 show Ga-based Mo under an applied magnetic field of 1000Oe₂Ga₂cMAX material and Ga-based magnetic material Mo₂(Ga_1-xFe_x)₂Comparison of the ZFC and FC diagrams of C shows that the Curie temperature is much higher than room temperature, further tests show that the Curie temperature is about 520 ℃, the Ga-based magnetic material obtained in the embodiment still keeps ferromagnetic property under a higher temperature condition, the material magnetism is more excellent, and the magnetic domain structure is more stable.

Testing of Ga-based Mo at 2K temperature₂Ga₂cMAX material and Ga-based magnetMo as raw material₂(Ga_1-xFe_x)₂The M-H curve of C, as shown in FIGS. 2 and 9, shows that Mo₂(Ga_1-xFe_x)₂The M-H curve of C is S-shaped, which shows that the obtained MAX phase material has magnetic property, the maximum saturation magnetization is 3.54emu/g, the remanent magnetization is about 1.4emu/g, the coercive force is close to 1470Oe, and the MAX phase material shows ferromagnetic property.

Example 2

Weighing Mo according to the molar ratio of 1:5:2:2₂Ga₂C nanopowder, NiCl₂NaCl and KCl, first Mo₂Ga₂C and NiCl₂Putting into a mortar, grinding for 15min until the mixture is uniformly mixed, adding NaCl and KCl into the mortar, and fully grinding for 10min to obtain a mixed material.

Placing the mixed material in a ceramic square boat, placing in a high-temperature tube furnace, introducing Ar gas at the flow rate of 5sccm, heating to 120 ℃ at the heating rate of 5 ℃/min, maintaining for 30min, heating to 475 ℃ at the heating rate of 5 ℃/min, keeping the temperature for 0.5h, naturally cooling to room temperature, and taking out the ceramic square boat.

The product in the ceramic ark was taken out and put into a 50 ml beaker, and 20ml of concentrated hydrochloric acid was slowly dropped and left to stand at 25 ℃ for reaction for 48 hours, to remove the metal oxide and the Ni cluster. Washing with deionized water and absolute ethyl alcohol for multiple times until the pH value is 7, and then drying for 12 hours at the temperature of 80 ℃ below zero and the vacuum degree of 5 Pa to obtain the Ga magnetic material Mo₂(Ga_1-xNi_x)₂C。

Mo obtained in example 2 by X-ray energy dispersive spectroscopy₂(Ga_1-xNi_x)₂C material is analyzed to obtain SEM Mapping graph, as shown in FIG. 10, Ni can be seen to enter Mo₂Ga₂And C, material.

Example 3

Weighing Mo according to the molar ratio of 1:3:3:2:2₂Ga₂C nanopowder, FeCl₂、NiCl₂NaCl and KCl, first Mo₂Ga₂C and FeCl₂、NiCl₂Placing into mortar, grinding for 15min to mix well,and adding NaCl and KCl into a mortar, and fully grinding for 10min to obtain a mixed material.

Placing the mixed material in a ceramic square boat, placing in a high-temperature tube furnace, introducing Ar gas at the flow rate of 5sccm, heating to 120 ℃ at the heating rate of 5 ℃/min, maintaining for 30min, heating to 500 ℃ at the heating rate of 5 ℃/min, keeping the temperature for 2h, naturally cooling to room temperature, and taking out the ceramic square boat.

The product in the ceramic ark was taken out and put into a 50 ml beaker, and 20ml of concentrated hydrochloric acid was slowly dropped and left to stand at 25 ℃ for reaction for 48 hours, to remove the metal oxide and the Fe and Ni clusters. Washing with deionized water and absolute ethyl alcohol for multiple times until the pH value is 7, and then drying for 12 hours at the temperature of 80 ℃ below zero and the vacuum degree of 5 Pa to obtain the Ga magnetic material Mo₂(Ga_1-x1-x2Fe_x1Ni_x2)₂C。

Mo obtained in example 3 by X-ray energy dispersive spectroscopy₂(Ga_1-x1-x2Fe_x1Ni_x2)₂C material is analyzed to obtain SEM Mapping graph, as shown in FIG. 11, Ni and Fe can be seen to enter Mo₂Ga₂And C, material.

Example 4

Weighing Nb according to the molar ratio of 1:5:2:2₂Ga₂C nanopowder, FeCl₂NaCl and KCl, Nb first₂Ga₂C and FeCl₂Putting into a mortar, grinding for 15min until the mixture is uniformly mixed, adding NaCl and KCl into the mortar, and fully grinding for 10min to obtain a mixed material.

Placing the mixed material in a ceramic square boat, placing in a high-temperature tube furnace, introducing Ar gas at the flow rate of 5sccm, heating to 120 ℃ at the heating rate of 5 ℃/min, maintaining for 30min, heating to 500 ℃ at the heating rate of 5 ℃/min, preserving heat for 8h, naturally cooling to room temperature, and taking out the ceramic square boat.

The product in the ceramic ark was taken out and put into a 50 ml beaker, and 20ml of concentrated hydrochloric acid was slowly dropped and left to stand at 25 ℃ for reaction for 48 hours, to remove the metal oxide and the Fe cluster. Washing with deionized water and anhydrous ethanol for multiple times until the pH value reaches 7, and freeze drying at-80 deg.CThe void degree is 5 Pa, and the Ga-based magnetic material Nb is obtained after drying for 12 hours₂(Ga_1-xFe_x)₂C。

Nb obtained in example 4 by X-ray energy dispersive Spectroscopy₂(Ga_1-xFe_x)₂C material is analyzed to obtain SEM Mapping graph, as shown in FIG. 12, Fe can be seen to enter Nb₂Ga₂And C, material.

Comparative example 1

Weighing Mo according to the molar ratio of 1:5:2:2₂Ga₂C nanopowder, FeCl₂NaCl and KCl, first Mo₂Ga₂C and FeCl₂Putting into a mortar, grinding for 15min until the mixture is uniformly mixed, adding NaCl and KCl into the mortar, and fully grinding for 10min to obtain a mixed material.

Placing the mixed material in a ceramic square boat, placing in a high-temperature tube furnace, introducing Ar gas at the flow rate of 5sccm, heating to 120 ℃ at the heating rate of 5 ℃/min, maintaining for 30min, heating to 700 ℃ at the heating rate of 5 ℃/min, preserving heat for 8h, naturally cooling to room temperature, and taking out the ceramic square boat.

The product in the ceramic ark was taken out and put into a 50 ml beaker, and 20ml of concentrated hydrochloric acid was slowly dropped and left to stand at 25 ℃ for reaction for 48 hours, to remove the metal oxide and the Fe cluster. Washing with deionized water and absolute ethyl alcohol for multiple times until the pH value is 7, and then drying for 12 hours by freeze drying at the temperature of 80 ℃ below zero and the vacuum degree of 5 Pa to obtain the product.

The product obtained in comparative example 1 was analyzed by a scanning electron microscope to obtain a scanning electron micrograph, and as shown in FIG. 13, Mo was observed₂Ga₂The morphology of C is greatly changed and contains more octahedral impurities. The material contains a large amount of iron oxide impurities, the appearance of the material is greatly changed, and the structure of the material is considered to be greatly changed according to XRD (see figure 14) and is not Mo any more₂Ga₂C MAX structure.

As can be seen from the above examples, in the present embodiment, M is preferably replaced by a divalent magnetic metal salt by the molten salt method₂Ga₂Ga in X is a magnetic element dissolved in the A site of Ga-based MAX phaseThe magnetic performance of the MAX phase is improved in one step. The optimal preparation method is simple and controllable, the required synthesis temperature is low, the time is short, and the method has important significance in expanding the family members of the MAX phase material, regulating and controlling the physical and chemical properties of the MAX phase material and the like.

In addition, the inventors of the present invention have conducted experiments by replacing the raw materials and process conditions described in the above embodiments with other raw materials and process conditions described in the present specification, and as a result, have shown that a Ga-based MAX phase material containing magnetic elements such as Mn, Fe, Co, and Ni at the a-site can be obtained.

The above description is only a preferred embodiment of the present invention, and it should be noted that various modifications to these embodiments can be implemented by those skilled in the art without departing from the technical principle of the present invention, and these modifications should be construed as the scope of the present invention.