The Fermi Surface in a Magnetic Metal–insulator Interface

Nickel (111) and the interface of hexagonal boron nitride on Ni(111) serve as model systems for an itinerant ferromagnet that is truncated with vacuum or a single layer insulator. These systems are investigated with angle-scanned He I and He II photoemission. Upon formation of the h-BN/Ni(111) interface the work function drops by 1.8 eV and the minority Ni Λ 3 d-band shifts by 0.13 eV to higher binding energy. This indicates that the Ni magnetic moment decreases in the interface. Spin-polarized band structure calculations from bulk nickel identify the observed minority and majority bands. The experimental Fermi surface maps show that h-BN distorts a minority d-band in a way which is consistent with the decreasing magnetic moment. It can be seen that h-BN affects the scattering of the electrons. Effects in the photoemission final and initial state are recognized.