Order-disorder transformation in the binary MPt3 and ternary CuMPt6 (M=3d metals) alloys

The order-disorder(O-D) transformation in the binary MPt₃ and the ternary CuMPt₆ (M=3d transition metals) alloys were studied. The O-D transformation temperatures (T_c) were calculated by combining the method of pseudopotentials with the static concentration waves. The method originally proposed by Khachaturyan [Progress in Materials Science, vol. 22, Pergamon Press Ltd., Oxford, 1978, pp. 47-49; Phys. Met. Metallography 13 (1962) 493; Sov. Phys. Solid State 5 (1963) 16; Sov. Phys. Solid State 5 (1963) 548] was applied to the case of ternary CuMPt₆ alloys by using the concept of a pseudoatom. It is found that this model predicts results that are consistent with the experimental data.