UNBIASED ACCESS TO EXCHANGE SPLITTING OF MAGNETIC BANDS USING THE MAXIMUM-ENTROPY METHOD

The experimental information about magnetic bands and their temperatur e dependence is distorted by Fermi distribution and apparatus function . The recovery of the spectral density constitutes an ill-posed invers ion problem. We have invoked the maximum entropy regularization to dec onvolute spin-resolved inverse photoemission data of Ni(110). The effe ctive energy resolution is hereby improved by a factor of 5 and struct ures below E(F), which are generally lost in inverse photoemission, ar e recovered. The temperature-dependent data for Ni reveal clearly a pa ir of spin-split bands. The splitting vanishes on approaching the Curi e temperature.