Solid state interdiffusions in epitaxial Fe/GaAs(001) heterostructures during ultrahigh vacuum annealings up to 450 °C

Bruno Lépine (1) , S. Ababou (1) , A. Guivarc’h , G. Jézéquel , S. Députier (2) , R. Guérin (3) , A. Filipe , A. Schuhl (4) , F. Abel (5) , C. Cohen (6) , A. Rocher (7) , J. Crestou (7)

1 IPR - Institut de Physique de Rennes
2 ISCR - Institut des Sciences Chimiques de Rennes
3 METIS - Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols
4 LPM - Laboratoire de physique des matériaux
5 INSP - Institut des Nanosciences de Paris
6 GPS - Groupe de Physique des Solides
7 CEMES - Centre d'élaboration de matériaux et d'études structurales

We have used a set of complementary experimental techniques to characterize an epitaxial structure (25 nm Fe)/GaAs(001) annealed at 450 °C under ultrahigh vacuum conditions. The solid state interdiffusion leads to the formation of an epitaxial reaction layer made of Fe2As patches embedded in a Ga rich Fe3Ga2−XAsX ternary phase. The epitaxial character of this layer explains how the usually reported epitaxial growth of Fe on GaAs performed in the temperature range of 175 to 225 °C is possible in spite of the species intermixing occurring at the interface. Moreover, the observed grains of Fe2As explain the decrease of magnetization at the interface in such contact, since Fe2As is an antiferromagnetic alloy.

Domaines: Physique [physics]; Matière Condensée [cond-mat]

Bruno Lépine, S. Ababou, A. Guivarc’h, G. Jézéquel, S. Députier, et al.. Solid state interdiffusions in epitaxial Fe/GaAs(001) heterostructures during ultrahigh vacuum annealings up to 450 °C. Journal of Applied Physics, 1998, 83 (6), pp.3077 - 3080. ⟨10.1063/1.367063⟩. ⟨hal-01743495⟩