Suppression of Mn segregation in Ge/Mn5Ge3 heterostructures induced by interstitial carbon

M.T. Dau (1) , V. Le Thanh (1) , T-G. Le (1) , A. Spiesser (1) , M. Petit (1) , L.A. Michez (1) , T.H. Ngo , D.L. Vu , Q.L. Nguyen , P. Sebban

1 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille

Mn 5 Ge 3 compound, with its room-temperature ferromagnetism and possibility to epitaxially grow on Ge, acts as a potential spin injector into group-IV semiconductors. It is shown that the realization of Ge/ Mn 5 Ge 3 heterostructures is highly hampered by Mn segregation toward the Ge growing surface. The Mn segregation length can be estimated in-situ and in real time by means of reflection high-energy electron dif- fraction. We present here an approach allowing to greatly reduce or even to prevent the Mn segregation, whose principle is based on filling the Mn 5 Ge 3 lattice with interstitial carbon atoms. In addition, we show that interstitial carbon in Mn 5 Ge 3 allows to enhance not only the Curie temperature of Mn 5 Ge 3 C x layers but also in the whole Ge/Mn 5 Ge 3 /Ge heterostructures.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

M.T. Dau, V. Le Thanh, T-G. Le, A. Spiesser, M. Petit, et al.. Suppression of Mn segregation in Ge/Mn5Ge3 heterostructures induced by interstitial carbon. Thin Solid Films, 2012, 520, pp.3410-3414. ⟨10.1016/j.tsf.2011.10.167⟩. ⟨hal-00697538⟩