Suppressed reflectivity due to spin-controlled localization in a magnetic semiconductor

FP Mena*, JF DiTusa, D van der Marel, G Aeppli, DP Young, A Damascelli, JA Mydosh

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

20 Citations (Scopus)

Abstract

The narrow gap semiconductor FeSi owes its strong paramagnetism to electron-correlation effects. Partial Co substitution for Fe produces a spin-polarized doped semiconductor. The spin polarization causes suppression of the metallic reflectivity and increased scattering of charge carriers, in contrast to what happens in other magnetic semiconductors, where magnetic order reduces the scattering. The loss of metallicity continues progressively even into the fully polarized state, and entails as much as a 25% reduction in average mean-free path. We attribute the observed effect to a deepening of the potential wells presented by the randomly distributed Co atoms to the majority spin carriers. This mechanism inverts the sequence of steps for dealing with disorder and interactions from that in the classic Al'tshuler Aronov approach-where disorder amplifies the Coulomb interaction between carriers-in that here, the Coulomb interaction leads to spin polarization which in turn amplifies the disorder-induced scattering.

Original languageEnglish
Article number085205
Pages (from-to)1 - 7
Number of pages7
JournalPhysical Review. B: Condensed Matter and Materials Physics
Volume73
Issue number8
DOIs
Publication statusPublished - Feb-2006

Keywords

  • ELECTRONIC-STRUCTURE
  • OPTICAL-PROPERTIES
  • SPECTRAL WEIGHT
  • FESI
  • METAL
  • FERROMAGNETISM
  • TRANSPORT
  • (GA,MN)AS
  • EXCHANGE
  • BEHAVIOR

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