Evidence of new high-pressure magnetic phases in Fe-Pt invar alloy

To investigate the magnetic properties of disordered Fe70Pt30 Invar alloy under high pressure, measurements of the real part of the AC susceptibility (chi) were made under pressure up to 7.5 GPa in the temperature range 4.2-385 K using a cubic anvil high-pressure apparatus. The Curie temperature (T-C) decreased with increasing pressure, and then, two new high-pressure magnetic phases appeared. These results show that the ferromagnetism of Fe-Pt Invar alloy becomes weaker, and the antiferromagnetic interaction becomes dominant with increasing pressure. (C) 2002 Elsevier Science B.V. All rights reserved.