Negative thermal expansion in cubic and tetragonal structure coexisted La(Fe,Si)13hydride

[摘要] In this research, the cubic and tetragonal crystal structure coexisted LaFe10.0Si3.0compound and its hydride have been prepared by the arc-melting method and the novel electrolytic hydriding. Furthermore, the crystal structure, magneticand negative thermal expansion (NTE) properties of LaFe10.0Si3.0and its hydride were investigated by the X-ray diffraction (XRD) and physical property measurement system (PPMS). Intriguingly, the NTE operation-temperature window of LaFe10.0Si3.0has been broadened significantly after introducing interstitial hydrogen atoms. The further magnetic characterizations combined with theoretical analysis reveal that the increase of ferromagnetic to paramagnetic transition temperature due to stronger Fe-Fe magnetic exchange interactions contribute to the broad NTE operation-temperature window in the LaFe10.0Si3.0hydride.

[发布机构] Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China^1;University of Chinese Academy of Sciences, Beijing, China^2;School of Materials Science and Engineering, Tianjin University, Tianjin, China^3

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Interstitial hydrogen;Magnetic characterization;Magnetic exchange interactions;Operation temperature;Paramagnetic transition;Property measurement;Tetragonal crystal structure;Tetragonal structure