Spontaneous generation of voltage in Gd-5(SixGe4-x) during a first-order phase transition induced by temperature or magnetic - art. no. 174110

The spontaneous generation of voltage has been observed during the first-or der magnetic-Martensitic phase transition process in Gd-5(SixGe4-x) alloys regardless of whether the transformation is triggered by temperature or mag netic field. Based on various experimental data we show that thermoelectric power is a major contributor to the observed voltage. The characteristics of the simultaneously recorded spontaneous voltage and the signal from a di fferential thermocouple attached to the sample are quite complex, indicatin g that thermal effects arising in this class of materials during the first- order phase transition ore nontrivial. The unusual dynamics of both the hea t release and absorption during the phase transformations in Gd-5(SixGe4-x) result in the appearance of temperature gradients and, therefore, thermoel ectricity.