TEMPERATURE-DEPENDENT STUDY OF THE PARTIALLY FILLED SURFACE-STATE ON TB(0001)

The partially filled, magnetically-active d-like surface state on Tb(0 001) was studied by photoemission and inverse photoemission at tempera tures above as well as below the bulk Curie temperature of Tb metal. U pon cooling, the weight of the occupied surface state increases, while that of the empty surface state decreases. No temperature-dependent e nergy shifts of the surface states and, hence, no indication of a Ston er-like behavior of the exchange splitting were found. The results can be interpreted on the basis of a generalized theory of magnetism, whi ch predicts a change of relative spectral weights of spin-majority and spin-minority subbands with temperature.