Structural Disorder and Magnetism in the Spin-Gapless Semiconductor CoFeCrAl

Abstract

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 B to 2.50 B per formula unit, in good agreement with experiment.

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Document Details

Document Type
Technical Report
Publication Date
Aug 24, 2016
Accession Number
AD1011065

Entities

People

  • Andrew O’connell
  • Arti Kashyap
  • D. J. Sellmyer
  • Parashu Kharel
  • Ralph Skomski
  • Renu Choudhary
  • Shah R. Valloppilly
  • Simeon Gilbert
  • Yung Huh
  • Yunlong Jin

Organizations

  • Indian Institute of Technology Mandi

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Band Gaps
  • Carrier Mobility
  • Crystal Structure
  • Curie Temperature
  • Density Functional Theory
  • Energy
  • Energy Bands
  • Fermi Levels
  • Heat Treatment
  • Magnetic Moments
  • Magnetic Properties
  • Materials
  • Physical Properties
  • Quantum Properties
  • Semiconductors
  • Superlattices
  • X Rays

Readers

  • International Journalism and Media Studies.
  • Powder metallurgy of Titanium alloys.
  • Quantum Chemistry

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene