Experimental evidence of pressure-induced magnetic phase transition in Fe72Pt28 Invar alloy

X-ray magnetic circular dichroism (XMCD) measurements have been performed u nder high pressure and used to study the disordered Fe72Pt28 Invar alloy in conjunction with x-ray diffraction. The high spin to low spin state transi tion is observed by both techniques and is compared with previous work. Fur thermore, XMCD gives the first evidence of the complete disappearance of th e magnetic moment at high pressure in this alloy. It also proves the existe nce of an hysteresis cycle due to the pressure-dependent magnetic moment. ( C) 1998 American Institute of Physics. [S0021-8979(98)41011-9].