Structure and Phase Transformation in the Giant Magnetostriction Laves-Phase SmFe2
- Univ. of Science and Technology Beijing, Beijing (China). Dept. of Physical Chemistry
- Univ. of Science and Technology Beijing, Beijing (China). State Key Lab. for Advanced Metals and Materials
- Argonne National Lab. (ANL), Argonne, IL (United States). X-Ray Science Division
- Chinese Academy of Sciences (CAS), Beijing (China). Key Lab. of Cryogenics, Technical Inst. of Physics and Chemistry
As one class of the most important intermetallic compounds, the binary Laves-phase is well-known for their abundant magnetic properties. Samarium-iron alloy system, SmFe2, is a prototypical Laves compound that shows strong negative magnetostriction but relatively weak magnetocrystalline anisotropy. SmFe2 has been identified as a cubic Fd$$ \overline{3}\ $$m structure at room temperature, however, the cubic symmetry does not match the spontaneous magnetization along the [111]cubic direction. Here we studied the crystal structure of SmFe2 by high-resolution synchrotron X-ray powder diffraction and X-ray total scattering methods. SmFe2 is found to adopt a centrosymmetric trigonal R$$ \overline{3}\ $$m structure at room temperature, which transforms to an orthorhombic Imma structure at 200 K. This transition is in agreement with the changes of easy magnetization direction from [111]cubic to [110]cubic direction, and is further evidenced by the inflexion of thermal expansion behavior, the sharp decline of the magnetic susceptibility in the FC-ZFC curve, and the anomaly in the specific heat capacity measurement. Lastly, the revised structure and phase transformation of SmFe2 could be useful to understand the magnetostriction and related physical properties of other RM2-type pseudo-cubic Laves-phase intermetallic compounds.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Natural Science Foundation of China (NSFC); Fundamental Research Funds for the Central Universities
- Grant/Contract Number:
- AC02-06CH11357; 21590793; 21231001; 21701008; FRF-TP-17-038A1
- OSTI ID:
- 1422564
- Journal Information:
- Inorganic Chemistry, Vol. 57, Issue 2; ISSN 0020-1669
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Structural, Magnetic, and Magnetoelastic Properties of High Nd-Content Laves Alloys Prepared by Solid-State Synthesis
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journal | May 2019 |
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