No abstract

X-ray magnetic circular dichroism (XMCD) measurements have been performed under high pressure and used to study the disordered Fe72Pt28 Invar alloy in conjunction with x-ray diffraction. The high spin to low spin state transition is observed by both techniques and is compared with previous work. Furthermore, XMCD gives the first evidence of the complete disappearance of the magnetic moment at high pressure in this alloy. It also proves the existence of an hysteresis cycle due to the pressure-dependent magnetic moment.

No abstract

X-ray magnetic circular dichroism (XMCD) measurements have been performed under high pressure and used to study the disordered Fe 72Pt28 Invar alloy. The well-known high spin to low spin state transition is observed at 4 GPa. In addition, XMCD evidences a second transition to the nonmagnetic phase at high pressure in the disordered alloy. This result is made unambiguous by comparison to the ordered alloy whose hysteresis cycle of the phase transitions is dramatically different from the disordered alloy. The pressure-dependent collapse of the Curie temperature is the dominant mechanism for reducing the magnetization only in the ordered alloy.