Evidence for the high-spin to low-spin state transition in orderedFe3Pt Invar

The electronic struture of ordered ${\mathrm{Fe}}_3$Pt Invar has been studied by spin- and angle-resolved photoemission with synchrotron radiation as a function of temperature between T/${\mathrm{T}}_{\mathrm{C}}$=0.58 and 1.3. An anomalous shift of photoemission intensities in the vicinity of ${\mathrm{E}}_{\mathrm{F}}$ is found to accompany the ferromagnetic phaes transition. This is interpreted semiquantitatively as resulting from the predicted changes in the electronic structure of fcc Fe occurring with the high-spin to low-spin state transition.