The orientation relationships and interfaces between δ-AuSn and Au

Abstract

The orientation relationships and interfaces of δ-AuSn with the Au (001), (110) and (111) surfaces have been studied with transmission electron microscopy. Au was evaporated onto the NaCl (001), (011) and (111) surfaces to form epitaxial Au thin films and Sn was evaporated onto the Au films to form δ-AuSn. Two types of orientation relationships have been found: (1) (11 2 ¯ 0 ) δ//(001) Au, (0001) δ//(110) Au, and (1 1 ¯ 00 ) δ// ( 1 ¯ 10 ) Au, which was found on the (11 2 ¯ 0 ) δ/(001) Au interface and the (1 1 ¯ 00 ) δ/ ( 1 ¯ 10 ) Au interfaces; and (2) (11 2 ¯ 0 ) δ// ( 1 ¯ 11 ) Au, (0001) δ//(110) Au, and (1 1 ¯ 00 ) δ// ( 1 ¯ 1 2 ¯ ) Au, which was found on the (11 2 ¯ 0 ) δ/ ( 1 ¯ 11 ) Au interface. The interfaces are analyzed by the structures of the surfaces and the orientation relationships. The nucleation of δ-AuSn on these interfaces is also discussed.