EXCHANGE SPLITTINGS OF MN-DERIVED AND SB-DERIVED STATES BY SPIN-RESOLVED VALENCE-BAND PHOTOEMISSION OF MNSB

We have grown epitaxial (0001)-oriented films of the ferromagnetic int ermetallic compound MnSb on GaAs(111) substrates. The ex situ grown sa mples can be reprepared in such a way that clean, ordered, and magneti cally saturated surfaces are obtained. Using spin-resolved photoemissi on, Sb5p- and Mn3d-derived spectral features are identified, and large exchange splittings (1.4 and 1.7 eV for Mn-Sb bonding states and abou t 3.0 eV for Mn nonbonding states) are measured. Our ab initio band-st ructure calculation agrees rather well with the experiment, reproducin g the exchange splittings of Mn-Sb states but slightly underestimating that of Mn states.