A NEW PHASE OF CU-PT ALLOY - THEORETICAL PREDICTION AND EXPERIMENTAL SUPPORT

The phase stability of the Cu-Pt alloy system is studied with the elec tronic structure theory and the Monte Carlo simulation, By introducing 20 multi-site interatomic interactions including 6-body and pairs up to 6-th nearest neighbor, we can reproduce experimentally observed pha ses. Furthermore, our first-principles calculations shows existence of a new phase near the stoichiometry of Cu7Pt where the L1(2) ordered s tructure is reported experimentally. A preliminary experiment has been made to check the crystal structure at this composition and the resul t supports our theoretical prediction.