Depth profile high-energy spectroscopic study of Mn-doped GaN prepared by thermal diffusion

摘要

We have performed an $in$-$situ$ depth profile study of Mn-doped GaN preparedby a low temperature thermal diffusion method using photoemission and x-rayabsorption spectroscopy. It was revealed from the core-level photoemissionmeasurements that Mn ions are diffused into a deep ($\sim$ 70 \AA) region ofthe GaN substrates and that the line shapes of Mn 3$d$ partial density ofstates obtained by resonant photoemission measurements was close to that ofGa$_{1-x}$Mn$_x$N thin films grown by molecular-beam epitaxy. From x-rayabsorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD)measurements at the Mn $L$-edge, it was revealed that the doped Mn ions were inthe divalent Mn$^{2+}$ state and primarily paramagnetic. In magnetizationmeasurements, weak hysteresis was detected in samples prepared using $p$-typeGaN substrates while samples using $n$-type GaN substrates showed onlyparamagnetism.