MARTENSITIC TRANSFORMATION AND ELASTIC PROPERTY OF THE ANTIFERROMAGNETIC AuMn-AuZn QUASIBINARY ALLOYS

The antiferromagnetic AuMn-AuZn quasibinary alloys undergo a martensitic transformation from the CsCl-type cubic (B2) to the tetragonal (tetragonally distorted B2) with the axial ratio c/a<1. This transformation was thermoelastic and of the 1st order, although it was close to the 2nd order transformation. The shape memory effect was also observed. The transformation temperature from cubic to tetragonal, Tt, was about 10 degrees lower than the Neel temperature of antiferromagnetism, TN, in this alloy system. The temperature dependence of the elastic constants was measured and the results were compared with those of Mn-Ni and Au-Zn alloys.