Pressure induced magnetic phase transition in Fe–Ni Invar alloy

The magnetic properties of an FCC Fe68.1Ni31.9 Invar alloy have been investigated under high pressure up to 7.7 GPa by AC susceptibility measurements in the temperature range from 4.2 to 400 K. Up to 5.5 GPa, the Curie temperature (<f>TC</f>) decreased linearly with increasing pressure. Above 3.5 GPa, a reentrant spin glass-like phase was observed clearly in the low-temperature region below 50 K. Above 5.5 GPa, ferromagnetic (FM) phase began to collapse with increasing pressure, and then at 7.7 GPa, FM phase disappeared, while the spin glass-like phase was still seen. Our results dearly show the pressure induced magnetic phase transition from the FM phase to the spin glass-like high-pressure magnetic phase. [Copyright &y& Elsevier]