Hydrogen and Magnetism in $Ga_{1-x}Mn_{x}As$

Abstract

Our recent studies of the influence of hydrogenation on the ferromagnetic semiconductor \(Ga_{1-x}Mn_{x}As\) are reviewed. We find that upon exposure to a remote DC hydrogen plasma, the hole density p in \(Ga_{1-x}Mn_{x}As\) thin films with \(x=0.037\) and \(x=0.051\) can be reduced by several orders of magnitude, while the density of Mn magnetic moments is not significantly affected by the plasma treatment. The ferromagnetism clearly present in the as-grown samples vanishes after hydrogen incorporation. We analyze the effect of the hydrogenation in detail with the help of secondary ion mass spectroscopy, electronic transport, Hall, DC magnetization, and Fourier-transform infra-red absorption experiments. All results indicate that the Mn acceptors are electrically passivated by the formation of Mn-As-H complexes, resulting in the loss of long-range magnetic ordering.