k -Space Mapping of Majority and Minority Bands on the Fermi Surface of Nickel below and above the Curie Temperature

A section through the three-dimensional Fermi surface of Ni has been mapped perpendicular to the [110] direction using angle-scanned photoemission. Regions of minority and majority spin bands, well separated in k space, can clearly be identified through comparison with a band structure calculation. The behavior of the different bands is observed for temperatures below and above the Curie temperature TC. We find bands which move and bands which stay in place for going from T<TC to T>TC.