Open AccessStructural disorder and magnetism in the spin-gapless semiconductor CoFeCrAl
Author(s) -
R. N. P. Choudhary,
Parashu Kharel,
Shah Valloppilly,
Yunlong Jin,
Andrew O’Connell,
Yung Huh,
Simeon Gilbert,
Arti Kashyap,
D. J. Sellmyer,
Ralph Skomski
Publication year - 2016
Publication title -
aip advances
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.421
H-Index - 58
ISSN - 2158-3226
DOI - 10.1063/1.4943306
Subject(s) - magnetism , condensed matter physics , ferrimagnetism , materials science , gapless playback , superlattice , magnetic moment , spin (aerodynamics) , half metal , semiconductor , magnetic semiconductor , electronic band structure , magnetization , ferromagnetism , physics , spintronics , thermodynamics , magnetic field , optoelectronics , quantum mechanics
Disordered CoFeCrAl and CoFeCrSi0.5Al0.5 alloys have been investigated experimentally and by first-principle calculations. The melt-spun and annealed samples all exhibit Heusler-type superlattice peaks, but the peak intensities indicate a substantial degree of B2-type chemical disorder. Si substitution reduces the degree of this disorder. Our theoretical analysis also considers several types of antisite disorder (Fe-Co, Fe-Cr, Co-Cr) in Y-ordered CoFeCrAl and partial substitution of Si for Al. The substitution transforms the spin-gapless semiconductor CoFeCrAl into a half-metallic ferrimagnet and increases the half-metallic band gap by 0.12 eV. Compared CoFeCrAl, the moment of CoFeCrSi0.5Al0.5 is predicted to increase from 2.01 μB to 2.50 μB per formula unit, in good agreement with experiment
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