ORDERING AND THE RELAXATION OF ELASTIC STRAIN IN THIN AU-NI FILMS GROWN ON AU(001)

Epitaxial Au1-xNix solid solutions with x ranging from 0.2 to 0.6 have been grown by MBE on Au(001) at room temperature. Their relaxation ha s been studied in-situ by RHEED and ex-situ by GIXD, TEM and HREM. All of the films studied relax via the introduction of a/6[211] partial d islocations and microtwins. Furthermore, alloys ranging in composition from 30 to 60 at.% Ni undergo an ordering process during growth in wh ich pseudo-periodic antiphase structures based on the L1(0) unit cell are formed. The origin of this state of order is attributed primarily to the large misfit existing between the alloy films and Au(001). Copy right (C) 1996 Acta Metallurgica Inc.