Effect of a magnetic field on the magnetostructural phase transition in Gd5(SixGe1-x)4

Abstract

The first-order magnetostructural phase transition in Gd5(SixGe1-x)4 alloys with x < ∼ 0.5 and the related entropy change ΔS are analyzed from high-field magnetization curves up to 23 T, and differential scanning calorimetry up to 5 T. The variation of the transition field Ht with the transition temperature Tt is discussed for fields up to 23 T for the x < ∼ x < ∼ 0.5), provided the Maxwell relation is evaluated only within the transition region. The T and H dependences of ΔS are accounted for by modeling the T and H dependences of the magnetization outside the transition. © 2004 The American Physical Society.