CrBr3 single crystal with magnetocaloric effect and preparation method and application thereof

A technology of magnetocaloric effect and single crystal, which is applied in the field of material CrBr3 single crystal with magnetocaloric effect and its preparation, can solve the problems of high toxicity, harmfulness and high risk, and achieve the effects of high energy utilization rate, simple equipment and good application prospect.

Inactive Publication Date: 2018-11-06
BEIJING UNIV OF POSTS & TELECOMM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

(Ichiro Tsubokawa, Journal of the physical society of Japan, 1960, 15...

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  • CrBr3 single crystal with magnetocaloric effect and preparation method and application thereof
  • CrBr3 single crystal with magnetocaloric effect and preparation method and application thereof
  • CrBr3 single crystal with magnetocaloric effect and preparation method and application thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0024] CrBr 3 The polycrystal is put into the quartz tube, and then vacuum sealed, the vacuum degree -3 Pa, a sealed quartz tube with a length of 20cm is obtained; put the sealed quartz tube into a tube furnace in a two-temperature zone, raise the temperature of the source zone at 41℃ per hour for 24 hours and control it at 984℃, and increase it at 34℃ per hour The temperature of the growth zone is 24 hours to 816°C; keep constant temperature for 120 hours; then cool to room temperature, the sample obtained is CrBr 3 Single crystal.

[0025] Such as figure 1 As shown in (a), the sample prepared above is a black flaky single crystal. X-ray diffraction measurement and analysis of the obtained crystal, the results are as follows figure 1 As shown in (b), the obtained crystal has a preferred orientation of (00l) direction, and (00l) represents the same crystal plane family. The result of electronic energy spectrum measurement shows that the atomic ratio of Cr to Br is 1:3, indicating...

Embodiment 2

[0029] CrBr 3 The polycrystal is put into the quartz tube, and then vacuum-sealed, the vacuum is less than 10 -3 Pa, get a sealed quartz tube with a length of 30cm; put the sealed quartz tube into a tube furnace with two temperature zones, raise the temperature of the source zone at a rate of 29°C per hour for 30 hours and control it at 870°C, at 30°C per hour Increase the temperature of the growth zone at 720 °C for 24 hours at a rate. Constant temperature for 150 hours, then cooled to room temperature, the sample obtained is CrBr 3 Single crystal.

[0030] The sample prepared above is a black flaky single crystal, and the obtained crystal is subjected to X-ray diffraction measurement and analysis, and the result shows that the obtained crystal has a preferred orientation in the (00l) direction. The result of electronic energy spectrum measurement shows that the atomic ratio of Cr to Br is 1:3, indicating that it is CrBr 3 Single crystal. A superconducting quantum interferomete...

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Abstract

The invention discloses a CrBr3 single crystal with a magnetocaloric effect and a preparation method and an application thereof, and belongs to the technical field of magnetic refrigeration materials.The preparation method includes placing a CrBr3 polycrystalline raw material into a quartz tube and form high vacuum; placing the quartz tube horizontally placed into a tubular furnace of a second temperature zone, heating a tubular furnace source zone and a growth zone simultaneously and then cooling to the room temperature after the temperature is constant to obtain the CrBr3 single crystal. The preparation method has low synthesis temperature, simple equipment and simple manufacturing process. The gas phase transport process is beneficial to the purification of the material, so that the single crystal has high purity and good quality. The prepared single crystal material has secondary phase transition of ferromagnetic to paramagnetic in 33K, is stable in performance under an applied magnetic field, and has large magnetic entropy change and relative cooling capacity. The preparation parameters are provided for development and application of magnetic refrigeration, and the single crystal can be used in the technical fields of high energy physics, low temperature engineering precision instruments, power industry and the like.

Description

Technical field [0001] The invention belongs to the technical field of magnetic refrigeration materials, in particular to a material with magnetocaloric effect CrBr 3 Single crystal and its preparation method. Background technique [0002] The magnetocaloric effect is a physical phenomenon in which a magnetic material releases or absorbs heat during the process of magnetization or demagnetization, and is an intrinsic property of a magnetic material. The physical quantity that characterizes the degree of magnetic order of a magnetic material is called magnetic entropy. When the magnetic ordering state of a magnetic material changes under the action of a magnetic field, it will cause the magnetic entropy to change and cause the magnetocaloric effect. For ferromagnetic materials, the maximum magnetic entropy change generally occurs near the Curie temperature. The technology that uses the magnetic heat effect of magnetic materials to achieve cooling is called magnetic refrigeration ...

Claims

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Application Information

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IPC IPC(8): C30B29/12C30B23/00H01F1/01H01F41/00
CPCC30B23/00C30B29/12H01F1/017H01F41/00
Inventor 张晓余骁昀王西惠吴真平陈政委
Owner BEIJING UNIV OF POSTS & TELECOMM
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