Enhancement of Curie temperature in Ga1-xMnxAs epilayers grown on cross-hatched InyGa1-yAs buffer layers

O. Maksimov, B. L. Sheu, G. Xiang, N. Keim, P. Schiffer, N. Samarth

Research output: Contribution to journalArticle

Abstract

Relaxed InyGa1-yAs epilayers grown on (001) GaAs are known to exhibit a cross-hatched surface with ridges running along the [110] and [11̄0] directions. We find that Ga1-xMnxAs epilayers grown on such buffer layers can have as-grown Curie temperatures (T C) that are higher than the as-grown 110K value typical of Ga 1-xMnxAs/GaAs heterostructures. Further, low-temperature annealing leads to only modest additional increases in TC, contrasting with the behavior in Ga1-xMnxAs/GaAs where TC typically increases significantly upon annealing. Our observations suggest that the initial concentration of Mn interstitials in as-grown Ga 1-xMnxAs /InyGa1-yAs heterostructures is smaller than that in as-grown Ga1-xMn xAs/GaAs heterostructures. We propose that strain-dependent diffusion may drive Mn interstitials from the bulk of the growing crystal to more benign locations on the ridged surface, providing a possible route towards defect-engineering in these materials.

Original languageEnglish (US)
Pages (from-to)298-303
Number of pages6
JournalJournal of Crystal Growth
Volume269
Issue number2-4
DOIs
StatePublished - Sep 1 2004

Keywords

  • A3. Molecular beam epitaxy
  • B1. GaMnAs
  • B2. Ferromagnetic semiconductors

ASJC Scopus subject areas

  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Enhancement of Curie temperature in Ga<sub>1-x</sub>Mn<sub>x</sub>As epilayers grown on cross-hatched In<sub>y</sub>Ga<sub>1-y</sub>As buffer layers'. Together they form a unique fingerprint.

  • Cite this