Transformations in the Gd-5(Si1.95Ge2.05) alloy induced by the temperatureand 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 held were studied. The virgin sample shows a transition from t he low-temperature phase rr to the high-temperature, low-resistance phase b eta'. After several temperature and/or magnetic field induced cycles of the Gd-5(Si1.95Ge2.05) alloy through the first-order phase transition, the alp ha 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 s imilar to7 K temperature difference; The observed phenomena are discussed b ased on the mechanism of the simultaneous magnetic/crystallographic phase t ransition in Gd-5(SixGe4-x).