Preparation method of binary rare earth compound beta-DyGa3
By adding an Al catalyst during the preparation of β-DyGa3 and growing single crystals by using the Ga-Al flux method, the problem of difficulty in preparing β-DyGa3 as a single phase sample was solved, and the possibility of studying its physicochemical properties and properties was realized.
Patent Information
- Application Number
- CN202411181498.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-27
- Publication Date
- 2024-12-17
AI Technical Summary
Since the binary rare earth compound β-DyGa3 is difficult to prepare as a single-phase sample, its physicochemical properties have not been studied so far and often coexist with other structures, resulting in its performance being unknown.
By adding the third element Al as a catalyst during the preparation of β-DyGa3, single crystals were grown by using the Ga-Al flux method to obtain pure β-DyGa3 product without other structures. The specific steps include heating in a vacuum quartz tube and gradually heating it Cooling, centrifugation separates the excess flux to obtain sheet-like single crystals.
A single-phase sample of pure β-DyGa3 was achieved, so that its physicochemical properties such as magnetic properties and thermal properties can be studied and its functional applications can be explored.
Smart Images
Figure CN119145035A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of rare earth materials, and in particular to a method for preparing a binary rare earth compound β-DyGa3. Background Art
[0002] Rare earth compounds are the core of rare earth functional materials, and their intrinsic properties are the basis and guarantee for the functional application of materials. For example, the permanent magnetic properties of rare earth permanent magnet materials depend on Nd2Fe 14 High saturation magnetization and strong magnetocrystalline anisotropy of rare earth compounds such as B and SmCo5. Rare earth giant magnetostrictive materials are based on the large spontaneous magnetostriction and small hysteresis loss of magnetostrictive compounds such as TbFe2 and SmFe2. The low-field application of the famous magnetostrictive material Terfenol-D is based on the magnetocrystalline anisotropy compensation of TbFe2 and DyFe2 compounds. The magnetocaloric properties of magnetocaloric materials strongly depend on the compounds Gd5(Ge,Si)4 and La(Fe,Si) 13 Therefore, studying new rare earth compounds may lead to the discovery of new application areas for rare earth materials and even the formation of new industries.
[0003] To study the structure and physicochemical properties of rare earth compounds, it is first necessary to prepare its single-phase samples. However, single-phase samples of some compounds are not easy to prepare. The binary rare earth compound DyGa3 is composed of only two elements, but has three different crystal structures: α-, β-, and γ-. Because they always have two or more structures at the same time, it is impossible to obtain a single-phase sample, and its physicochemical properties have been unknown for a long time.
[0004] β-DyGa3 has P63 / mmc symmetry, and its crystal structure is as follows Figure 1 As shown, it can be regarded as [DyGa3] layers tightly stacked along the crystallographic c-axis. Dy atoms occupy three different crystal positions, namely Dy(1)(0,0,1 / 4) at 2b, Dy(2)(1 / 3,2 / 3,0.0458) at 4f, and Dy(3)(1 / 3,2 / 3,0.6512) at 4f, forming three types of [DyGa3] layers A, B, and C. In a unit cell, there are 10 such [DyGa3] layers, and the stacking order is CBABCBCACB. Since there has been no single-phase β-DyGa3 sample, its physical and chemical properties have not been reported so far. Summary of the invention
[0005] The purpose of the present invention is to provide a method for preparing a binary rare earth compound β-DyGa3.
[0006] A method for preparing a binary rare earth compound β-DyGa3, wherein a third element Al is added as a catalyst during the preparation of β-DyGa3 to obtain a pure β-DyGa3 product free of DyGa3 of other structures;
[0007] The specific steps are as follows:
[0008] Step 1: Growing a single crystal using a Ga-Al flux method, mixing Dy, Ga and Al in a molar ratio of Dy:Ga:Al=1:20:5;
[0009] Step 2: Place the mixture into an alumina crucible and seal it in a vacuum quartz tube.
[0010] Step 3: The sealed quartz tube is placed in a muffle furnace, heated to 1080°C within 10 hours, kept warm for 8 hours, and then gradually cooled to 430°C at a rate of 3°C / h. At this temperature, the quartz tube is quickly taken out, and the excess Ga-Al flux is centrifuged to obtain a pure β-DyGa3 product in the form of a single crystal.
[0011] Furthermore, the typical size of the sheet single crystal in step 3 is 3×3×0.5 mm 3 .
[0012] Furthermore, the Ga-Al flux method is to add Al during the preparation of β-DyGa3, and Al acts as a catalyst in the preparation process.
[0013] Furthermore, the centrifugal separation in step three is carried out at a centrifugal temperature of 300°C-600°C.
[0014] The beneficial effects of the present invention are as follows: by using the preparation method described in the present invention, a pure β-DyGa3 product in the form of a single crystal of flakes can be obtained, which does not contain α-DyGa3 and γ-DyGa3 that often coexist with it. With a single-phase sample, we can study the melting point, magnetic ordering temperature, magnetic moment and magnetic structure and other magnetic properties of β-DyGa3, thermal properties such as electronic specific heat and Debye temperature, resistance at different temperatures and the law of resistance change with temperature and other physical properties and explore its other functional applications. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 Schematic diagram of the crystal structure of the binary rare earth compound β-DyGa3. DETAILED DESCRIPTION
[0016] The present invention will be further described below in conjunction with the embodiments and the accompanying drawings, but is not limited thereto.
[0017] Example 1
[0018] A method for preparing a binary rare earth compound β-DyGa3, wherein a third element Al is added as a catalyst during the preparation of β-DyGa3 to obtain a pure β-DyGa3 product free of DyGa3 of other structures;
[0019] Step 1: Mix high-purity raw materials Dy (purity of 99.9%), Ga (purity of 99.99%), and Al (purity of 99.99%) in a molar ratio of Dy:Ga:Al=1:20:5, with a total mass of 5 grams.
[0020] Step 2: Load the raw material mixture into an alumina crucible and then seal it in a vacuum quartz tube.
[0021] Step 3: The sealed quartz tube is placed in a muffle furnace, heated to 1080°C within 10 hours, kept warm for 8 hours, and then gradually cooled to 430°C at a rate of 3°C / h. At this temperature, the quartz tube is quickly taken out and centrifuged to remove excess Ga-Al flux. The centrifugal temperature is 450°C, and a pure β-DyGa3 product in the form of a single crystal is obtained. The size of the single crystal is 3×3×0.5mm 3 . Figure 1 Schematic diagram of the crystal structure of the binary rare earth compound β-DyGa3.
[0022] Matters not covered by the present invention are known technologies.
[0023] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.
Claims
1. A method for preparing a binary rare earth compound β-DyGa3, characterized in that: By adding the third element Al as a catalyst during the preparation of β-DyGa3, a pure β-DyGa3 product without DyGa3 of other structures is obtained; The specific steps are as follows: Step 1: Growing a single crystal using a Ga-Al flux method, mixing Dy, Ga and Al in a molar ratio of Dy:Ga:Al=1:20:5; Step 2: Place the mixture into an alumina crucible and seal it in a vacuum quartz tube. Step 3: Place the sealed quartz tube in a muffle furnace, heat to 1080°C within 10 hours, keep warm for 8 hours, and then gradually cool to 430°C at a rate of 3°C / h. Take out the quartz tube at this temperature, centrifuge to separate the excess Ga-Al flux, and obtain a pure β-DyGa3 product in the form of a single crystal.
2. The method for preparing the binary rare earth compound β-DyGa3 according to claim 1, characterized in that: Step 3: The size of the sheet single crystal is 3×3×0.5mm 3 .
3. The method for preparing the binary rare earth compound β-DyGa3 according to claim 1, characterized in that: The Ga-Al flux method is to add Al during the preparation of β-DyGa3, and Al acts as a catalyst in the preparation process.
4. The method for preparing the binary rare earth compound β-DyGa3 according to claim 1, characterized in that: The centrifugal temperature of step 3 centrifugal separation is 300°C-600°C.