For the purpose to elucidate the character of the interface between An metal and alpha-Sn films, Au metal thin films deposited on alpha-Sn(111) surfaces grown on InSb(111)A substrates are examined by using reflection high-energy electron diffraction (RHEED). The (111) surface of the alpha-Sn film with only the 3 x 3 reconstruction grown at 50 degrees C is used as a well-defined alpha-Sn(111) substrate for the growth of Au films. NiAs-type AuSn films with a high crystallinity are grown in the 1.1-nm-thick Au-deposited thin films on the alpha-Sn(111) held at room temperature (RT). The NiAs-type AuSn films have a 2 x 2 reconstructed surface structure. The orientation relationships between the AuSn and the alpha-Sn films are (001) AuSn//(111) alpha-Sn and [210]AuSn//[2 (1) over bar(1) over bar] alpha-Sn. On the other hand, at 60 degrees C, the AuSn with a high crystallinity grows in Au-deposited films of about 2.8 mn in thickness, although at RT the AuSn with a high crystallinity grows in Au-deposited films of about 1.1 nm in thickness as stated above. The difference of Au-deposited film thickness between them results from the difference of their interdiffusion lengths of An and Sn atoms, which depend on the temperature. Taking the interdiffusion into account, the properties and the formation mechanism of interfaces between An metal thin films as an electrode and the alpha-Sn/InSb semiconductor superlattice are discussed. (c) 2007 Elsevier B.V. All rights reserved.