The transformation of the magnetostructural phase transition with Ti addition in Gd5Si2Ge2

Abstract

The magnetic, thermal expansion and magnetostriction measurements of Gd5-xTixSi2Ge2 (x=0, 0.05, 0.1) compounds have been carried out in wide range of fields and temperatures. It is found that Ti addition leads to the disappearance of the structural transformation, the change of the order of the phase transition and the decrease of the hysteresis. The large positive magnetostriction associated with the structural phase transition in Gd5Si2Ge2 changes to the small negative one associated with the magnetic phase transition in Gd4.9Ti0.1Si2Ge2. The linear dependence of volume magnetostriction on the square of magnetization obtained for all investigated compounds is explained using the thermodynamic theory.