Magnetism, electron transport and effect of disorder in CoFeCrAl

P. Kharel, W. Zhang, R. Skomski, S. Valloppilly, Y. Huh, R. Fuglsby, S. Gilbert, D. J. Sellmyer

Research output: Contribution to journalArticle

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Abstract

Structural, electronic, and magnetic properties of a Heusler-type CoFeCrAl alloy have been investigated experimentally and by model calculations, with a focus on the alloy's spin-gapless semiconductivity. The as-quenched samples are ferrimagnetic at room temperature with a Curie temperature of about 456 K, which increases to 540 K after vacuum annealing at 600°C for 2 h. The saturation magnetizations of the as-quenched and 600°C-annealed samples are 1.9 μB/f.u. and 2.1 μB/f.u., respectively, which are very close to the value predicted by the Slater-Pauling curve. The resistivity shows a nearly linear decrease with increasing temperature, from about 930 μΩ cm at 5 K to about 820 μΩ cm at 250 K, with dρ/dT of about -5 × 10-7 Ω cm K-1. We explain this high resistivity and its temperature dependence as imperfect spin-gapless semiconducting behavior, with a negative band-gap parameter of 0.2 eV.

Original languageEnglish (US)
Article number245002
JournalJournal of Physics D: Applied Physics
Volume48
Issue number24
DOIs
StatePublished - Jun 24 2015

Fingerprint

Magnetism
disorders
electrical resistivity
Curie temperature
electrons
Saturation magnetization
magnetic properties
saturation
Electronic properties
Temperature
magnetization
vacuum
temperature dependence
annealing
Structural properties
Magnetic properties
Energy gap
room temperature
curves
electronics

Keywords

  • Heusler alloys
  • disorder
  • spin gapless semiconductor

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Acoustics and Ultrasonics
  • Surfaces, Coatings and Films

Cite this

Magnetism, electron transport and effect of disorder in CoFeCrAl. / Kharel, P.; Zhang, W.; Skomski, R.; Valloppilly, S.; Huh, Y.; Fuglsby, R.; Gilbert, S.; Sellmyer, D. J.

In: Journal of Physics D: Applied Physics, Vol. 48, No. 24, 245002, 24.06.2015.

Research output: Contribution to journalArticle

Kharel, P, Zhang, W, Skomski, R, Valloppilly, S, Huh, Y, Fuglsby, R, Gilbert, S & Sellmyer, DJ 2015, 'Magnetism, electron transport and effect of disorder in CoFeCrAl', Journal of Physics D: Applied Physics, vol. 48, no. 24, 245002. https://doi.org/10.1088/0022-3727/48/24/245002
Kharel P, Zhang W, Skomski R, Valloppilly S, Huh Y, Fuglsby R et al. Magnetism, electron transport and effect of disorder in CoFeCrAl. Journal of Physics D: Applied Physics. 2015 Jun 24;48(24). 245002. https://doi.org/10.1088/0022-3727/48/24/245002
Kharel, P. ; Zhang, W. ; Skomski, R. ; Valloppilly, S. ; Huh, Y. ; Fuglsby, R. ; Gilbert, S. ; Sellmyer, D. J. / Magnetism, electron transport and effect of disorder in CoFeCrAl. In: Journal of Physics D: Applied Physics. 2015 ; Vol. 48, No. 24.
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