Transformations in the Gd5(Si1.95Ge2.05) alloy induced by the temperature and magnetic-field cycling through the first-order magnetic-martensitic phase transition -: art. no. 064426

Temperature dependencies of the de electrical resistivity, de magnetization, and heat capacity of virgin Gd-5(S1.95Ge2.05) samples and after they had been cycled through the first-order phase transition by varying temperature or magnetic field were studied. The virgin sample shows a transition from the low-temperature phase rr to the high-temperature, low-resistance phase beta'. After several temperature and/or magnetic field induced cycles of the Gd-5(Si1.95Ge2.05) alloy through the first-order phase transition, the alpha phase transforms to beta" where beta" is the high-resistance: phase. The dc magnetization and zero magnetic field heat capacity data indicate that the temperature of the alpha --> beta" phase transition is lower by similar to2 K relative to alpha --> beta'. while the electrical resistance shows similar to7 K temperature difference. The observed phenomena are discussed based on the mechanism of the simultaneous magnetic/crystallographic phase transition in Gd-5(SixGe4-x).