Microstructure and spin polarization of quaternary Co2Cr1-xVxAl, Co2V1-xFexAl and Co2Cr1-xFexAl Heusler alloys

S. V. Karthik, A. Rajanikanth, Y. K. Takahashi, T. Ohkubo, K. Hono

Research output: Contribution to journalArticlepeer-review

44 Citations (Scopus)

Abstract

The microstructures, magnetic properties and spin polarization of quaternary Co2Cr1-xVxAl, Co2V1-xFexAl and Co2Cr1-xFexAl alloys were investigated. Phase separation into A2 and B2/L21 structure occurs in Co2CrAl and Co2Cr0.6Fe0.4Al, whereas Co2FeAl exhibits a single-phase B2 structure. The ordered L21 structure becomes more stable with increasing vanadium concentration (x ≥ 0.35). The saturation magnetization measured at 5 K for Co2Cr1-xVxAl alloy changes from 1.4 to 2.0 μB when x increases from 0.0 to 0.5 and then becomes 1.4 μB for x = 1.0. This behavior can be attributed to the variation in the local magnetic moment of Co atoms. The saturation magnetization of Co2V1-xFexAl and Co2Cr1-xFexAl alloys increases with increasing Fe concentration. The spin polarization decreases from 0.62 to 0.56 with increasing x for Co2Cr1-xFexAl alloy. Also, the spin polarization decreases with increasing x for Co2Fe1-xVxAl and Co2Cr1-xVxAl alloys. Possible reasons for the reduced spin polarization in these alloys are discussed.

Original languageEnglish
Pages (from-to)3867-3874
Number of pages8
JournalActa Materialia
Volume55
Issue number11
DOIs
Publication statusPublished - 2007 Jun
Externally publishedYes

Keywords

  • Half-metals
  • Heusler alloys
  • Microstructure
  • Spin polarization

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

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