K-edge resonant x-ray magnetic scattering from a transition-metal oxide: NiO

Abstract

We report the observation of resonant x-ray magnetic scattering in the vicinity of the Ni {ital K} edge in the antiferromagnet NiO. An approximately twofold increase in the scattering is observed as the incident photon energy is tuned through a pre-edge feature in the absorption spectrum, associated with quadrupolar (1s{r_arrow}3d) transitions. No enhancement is observed at the dipolar (1s{r_arrow}4p) maximum. The quadrupolar resonant scattering amplitude is estimated to be {approximately}0.01r{sub 0}. {copyright} {ital 1997} {ital The American Physical Society}