Zero Thermal Expansion and Ferromagnetism in Cubic Sc_1-xM_xF₃ (M = Ga, Fe) over a Wide Temperature Range

Journal Article · Thu Sep 18 04:00:00 EDT 2014 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja5077487· OSTI ID:1240407

Hu, Lei ^[1]; Chen, Jun ^[1]; Fan, Longlong ^[1]; Ren, Yang ^[2]; Rong, Yangchun ^[1]; Pan, Zhao ^[1]; Deng, Jinxia ^[1]; Yu, Ranbo ^[1]; Xing, Xianran ^[1]

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1. Univ. of Science and Technology, Beijing (China)
2. Argonne National Lab. (ANL), Argonne, IL (United States)

The rare physical property of zero thermal expansion (ZTE) is intriguing because neither expansion nor contraction occurs with temperature fluctuations. Most ZTE, however, occurs below room temperature. It is a great challenge to achieve isotropic ZTE at high temperatures. Here we report the unconventional isotropic ZTE in the cubic (Sc_1-xM_x)F₃ (M = Ga, Fe) over a wide temperature range (linear coefficient of thermal expansion (CTE), α_l = 2.34 × 10^-7 K^-1, 300-900 K). Such a broad temperature range with a considerably negligible CTE has rarely been documented. The present ZTE property has been designed using the introduction of local distortions in the macroscopic cubic lattice by heterogeneous cation substitution for the Sc site. Even though the macroscopic crystallographic structure of (Sc_0.85Ga_0.05Fe_0.1)F₃ adheres to the cubic system (Pm3^-m) according to the results of Xray diffraction, the local structure exhibits a slight rhombohedral distortion. This is confirmed by pair distribution function analysis of synchrotron radiation Xray total scattering. This local distortion may weaken the contribution from the transverse thermal vibration of fluorine atoms to negative thermal expansion, and thus may presumably be responsible for the ZTE. In addition, the present ZTE compounds of (Sc_1-xM_x)F₃ can be functionalized to exhibit high-T_c ferromagnetism and a narrow-gap semiconductor feature. The present study shows the possibility of obtaining ZTE materials with multifunctionality in future work.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science; Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source; National Natural Science Foundation (NSFC) (China)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1240407
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 39 Vol. 136; ISSN 0002-7863
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY