Local structures of III-V diluted magnetic semiconductorsGa1−xMnxAsstudied using extended x-ray-absorption fine structure

Abstract

Local structures around Mn in ${\mathrm{Ga}}_{1-x}{\mathrm{Mn}}_x\mathrm{As}$ ($x=0.005\mathrm{}$ and 0.074) films have been studied using Mn $K$-edge extended x-ray-absorption fine structure. In the ${\mathrm{Ga}}_{1-x}{\mathrm{Mn}}_x\mathrm{As}$ films, Mn atoms are substituted into the Ga sites in the zinc-blende-type GaAs lattice. The Mn-As bond length (2.49–2.50 Å) in ${\mathrm{Ga}}_{1-x}{\mathrm{Mn}}_x\mathrm{As}$ is 2–3 % larger than the Ga-As bond length (2.44 Å) in bulk GaAs. The longer Mn-As bonds cause local disorder in the GaAs lattice, the degree of which increases with the Mn composition.