Effect of Pressure on the Thermal Expansion of Fe₇₂Pt₂₈ Invar Alloy

抄録

The thermal expansion of disordered Fe₇₂Pt₂₈ Invar alloy has been measured under high pressure up to 2. 2 Gpa in order to clarify pressure effect of spontaneous volume magnetostriction ω_s. Anomalous volume expansion is observed below the Curie temperature T_C both at ambient pressure and high pressures. With increasing pressure, T_C decreases largely with a rate of dT_C/dP=-51 K/GPa. Temperature dependence of ω_s is estimated by considering phonon term of thermal expansion ω_ph (T). ω_s decreases largely with increasing pressure around T_C.