Interstitial manganese in (Ga,Mn)As detected by electron paramagnetic resonance

Various types of Mn in epitaxially grown (Ga,Mn)As have been investigated. Ionized interstitial manganese donors Mn-1(2+) have been found to occur in (Ga,Mn)As at dopant concentrations as low is 0.5%. A comparison with spectra from interstitial Mn-1(2+) inside bulk,doped GaAs:Mn yields a slight decrease of 1.5% in the hyperfine splitting with increasing dopant concentration. This is attributed to an increase in the lattice constant of(Ga,Mn)As with increasing manganese concentration. Contrary to Mn interstitials, Mn dopants on Ga lattice sites acts as acceptors. It is shogun that Mn on Ga lattice sites Mn-Ga(+2) is non- uniformly distributed. A low percentage of isolated Mn acceptors can he distinguished from the exchange broadened Mn-Ga(2+) signal. Thus, electron paramagnetic resonance is a promising tool for the investigation of (Ga,Mn)As and the classification of various types of Mn dopants responsible for the magnetic properties of(Ga,Mn)As (c) 2005 Elsevier Ltd. Pill rights reserved.