Rareearth-iron base compound magnetic refrigeration material with large magnetic entropy change and preparation process thereof

A technology of magnetic refrigeration materials and compounds, applied in the direction of magnetic materials, magnetic objects, machine operation methods, etc., can solve the problems that it is difficult to meet the requirements of magnetic refrigeration materials, and achieve the effect of abundant raw materials, simple preparation process and low cost

Inactive Publication Date: 2006-01-11
INST OF PHYSICS - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] To sum up, it is difficult for existing materials to meet the basic requirements of practical magnetic refrigeration materials that the Curie point can be adjusted in a wide range through composition changes while maintaining a large magnetic entropy change.

Method used

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  • Rareearth-iron base compound magnetic refrigeration material with large magnetic entropy change and preparation process thereof
  • Rareearth-iron base compound magnetic refrigeration material with large magnetic entropy change and preparation process thereof
  • Rareearth-iron base compound magnetic refrigeration material with large magnetic entropy change and preparation process thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0142] Embodiment 1 prepares LaFe 13-z Si z (z=1.2, 1.4, 1.6)

[0143] Preparation of LaFe by chemical formula 13-z Si z (z=1.2,1.4,1.6) compound, concrete process is:

[0144] i) Press LaFe 13-z Si z (z=1.2, 1.4, 1.6) chemical formula weighing, mixing commercially available rare earth metal La, R, Fe, M and Si raw materials with a purity higher than 99.9%, wherein La is excessively 10% (atomic percentage) to compensate volatilization and burning damage;

[0145] ii) Put the raw materials prepared in step i) into the electric arc furnace, and evacuate to 2×10 -5 Torr and above, after cleaning 1 or 2 times with the usual high-purity argon cleaning method, use the usual method to repeatedly flip and melt for 3 times under the protection of high-purity argon at 1 atmosphere, until the melting temperature reaches melting;

[0146] iii) Cooling in a copper crucible to obtain the as-cast alloy; wrap the as-cast alloy with molybdenum foil, seal it in a vacuum quartz tube, ann...

Embodiment 2

[0153] Embodiment 2 prepares LaFe 11.5 Si 1.5 h α(α=0, 0.3, 0.6, 0.9, 1.3, 1.5, 1.8)

[0154] First, prepare LaFe by the technique of embodiment 1 11.5 Si 1.5 Master alloy, and then further prepare its interstitial hydride: Put the small fragments of the master alloy into the autoclave, add 5MPa high-purity H 2 Closed in an autoclave. Keep absorbing H at 150°C 2 The time is 2 hours, and the saturated hydride LaFe with α = 1.8 is obtained 11.5 Si 1.5 h 1.8 , and then dehydrogenated in a vacuum quartz tube for 40, 30, 20, 10 and 5 minutes at 250° C. to obtain interstitial hydrides of α=0.3, 0.6, 0.9, 1.3, and 1.5, respectively.

[0155] The example compound LaFe 11.5 Si 1.5 h α (α=0, 0.3, 1.3, 1.8) room temperature XRD lines such as Figure 5 shown. It can be seen from the figure: i) and LaFe 11.5 Si 1.5 h α (α=0) same as master alloy, interstitial hydride LaFe 11.5 Si 1.5 h α (α=0.3, 1.3, 1.8) all keep cubic NaZn 13 type structure, and the single-phase prop...

Embodiment 3

[0158] Example 3 Preparation of La(Fe 1-y mn y ) 11.7 Si 1.3 h α (y=0~0.03, α=0, 2.0)

[0159] Prepare La(Fe by embodiment 2 1-y mn y ) 11.7 Si 1.3 h α (y=0-0.03, α=0, 2.0) compounds, wherein Mn is added in excess of 10% (atomic percentage) to compensate for volatilization and burning loss during smelting.

[0160] Figure 9 shows that La(Fe 1-y mn y ) 11.7 Si 1.3 Room temperature XRD lines of the samples, as shown. It can be seen from the figure: i) and LaFe 11.7 Si 1.3 Like the master alloy, La(Fe 1-x mn x ) 11.7 Si 1.3 (y=0.01, 0.02, 0.03) are cubic NaZn 13 type structure, for y = 0.02 and 0.03, a small amount of α-Fe appeared; ii) the substitution of Fe by trace amount of Mn makes the lattice constant slightly increased, which is mainly due to the fact that the atomic radius of Mn is slightly higher than that of Fe due to the radius.

[0161] Figure 10 shows that under the condition of 100 Gauss, the compound La(Fe 1-y mn y ) 11.7 Si 1.3 h α (...

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Abstract

The present invention relates to a rare earth-iron base compound magnetic refrigeration material with large magnetic entropy change and its preparation method. Its chemical general formula is La1-xRx(Fe1-yMy)13-zSizX alpha, in which R is more than one rare earth elements and its combination, M is more than one kind of Al, Co and Ga, etc. and its combination, X ix more than one kind of C, H, N and combination of them, x is 0-0.4, y is 0-0.3, z is 0-3.0 and alpha is 0.3.0. Its preparation method includes the following steps: utilizing direct smelting and annealing treatment to can prepare La1-xRx(Fe1-yMy)13-zSiz and low C-content La1-xRx(Fe1-yMy)13-zSiz alpha gap compound, and utilizing smelting, quickly-quenching and annealing treatment to prepare high C-content La1-xRx(Re1-yMy)13-zSizC alpha gas compound.

Description

technical field [0001] The invention relates to a magnetic material, in particular to a rare earth-iron-based compound magnetic refrigeration material with large magnetic entropy change and a preparation method thereof. Background technique [0002] Traditional gas compression refrigeration technology is widely used in various industries and has formed a huge industry, but it has disadvantages such as low refrigeration efficiency, high energy consumption, and damage to the atmospheric environment. [0003] Magnetic refrigeration refers to a new type of refrigeration technology that uses magnetic materials as refrigerants. When the magnetic field strength increases (magnetization), the magnetic moments of the magnetic refrigeration material tend to be arranged in an orderly manner, the magnetic entropy decreases, and heat is released to the outside; when the magnetic field strength is weakened (demagnetization), the magnetic moments tend to be arranged in disorder, As the ma...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C38/00H01F1/058F25B21/00
CPCY02B30/66Y02B30/00
Inventor 陈远富沈保根王芳胡凤霞王光军
Owner INST OF PHYSICS - CHINESE ACAD OF SCI
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