Understanding high ordering temperature in Gd6FeBi2 magnet : Critical behavior, electronic structure and crystal-field analysis

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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Author(s)

  • Guoming Cui
  • Kam Wa Wong
  • Guangcun Shan
  • Jiliang Zhang

Detail(s)

Original languageEnglish
Article number166301
Journal / PublicationJournal of Magnetism and Magnetic Materials
Volume499
Online published14 Dec 2019
Publication statusPublished - 1 Apr 2020

Abstract

Gd6FeBi2 is reported as the only one room-temperature magnet among more than hundreds of compounds with its structural type, which makes it more attractive in potential applications. To reveal the origin of such high ordering temperature, critical behaviors, electronic structure and crystal-field effects of Gd6FeBi2 are investigated in this work. The short-range Gd-Fe ferrimagnetic interaction is supported by the crystal and electronic structure analyses. Unlike the strong Fe-Fe exchange interactions, the Gd-Fe exchange interaction shows limited influence on the critical exponents determined by long-range exchange interactions, which seems a common feature in rare earth – transition metal based alloys without exchange interactions between transition-metal atoms. However, the strong Gd-Fe hybridization reduces the influence of vibronic couplings on the short-range exchange interaction and thus allows a high Tc. The broadening or splitting mechanism of Gd 4f-electron bands is addressed based on crystal-field analysis and likely another factor for elevated Tc in Gd6FeBi2 and Gd-based compounds with non-magnetic elements. Different magnetic behaviors among isostructural compounds, and the relationship between the band splitting and crystal-field effects is also discussed.

Research Area(s)

  • Crystal and ligand fields, Electronic band structure, Magnetisation, Rare earth alloys and compounds

Citation Format(s)

Understanding high ordering temperature in Gd6FeBi2 magnet : Critical behavior, electronic structure and crystal-field analysis. / Cui, Guoming; Ma, Huan; Wong, Kam Wa; Shek, Chan Hung; Shan, Guangcun; Zhang, Jiliang.

In: Journal of Magnetism and Magnetic Materials, Vol. 499, 166301, 01.04.2020.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal