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Author Zhang, Jiliang ♦ Zheng, Zhigang ♦ Shan, Guangcun ♦ Bobev, Svilen ♦ Shek, Chan Hung
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ATOMS ♦ DISTANCE ♦ ELECTRONIC STRUCTURE ♦ ENTROPY ♦ MAGNETIC PROPERTIES ♦ PARAMAGNETISM ♦ SPIN ♦ THERMAL EXPANSION ♦ X-RAY PHOTOELECTRON SPECTROSCOPY
Abstract The structure of known Gd{sub 4}Co{sub 3} compound is re-determined as Gd{sub 6}Co{sub 4.85}, adopting the Gd{sub 6}Co{sub 1.67}Si{sub 3} structure type, which is characterized by two disorder Co sites filling the Gd octahedral and a short Gd-Gd distance within the octahedra. The compound shows uniaxial negative thermal expansion in paramagnetic state, significant negative expansion in ferromagnetic state, and positive expansion below ca. 140 K. It also exhibits large magnetocaloric effect, with an entropy change of −6.4 J kg{sup −1} K{sup −1} at 50 kOe. In the lattice of the compound, Co atoms at different sites show different spin states. It was confirmed by the X-ray photoelectron spectra and calculation of electronic structure and shed lights on the abnormal thermal expansion. The stability of such compound and the origin of its magnetism are also discussed based on measured and calculated electronic structures.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-10-07
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 118
Issue Number 13


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