K-edge resonant x-ray magnetic scattering from RbMnF3

Magnetic resonant x-ray scattering experiments at the Mn K edge have revealed the occurrence of two different resonances in antiferromagnetic RbMnF3. Below the K edge, at the 3d threshold, the resonance profile is consistent with quadrupole electrical transitions from the Is core level to the 3d states; the observed resonance amplitude corresponds to the expected value for spin-orbit splitting in 3d levels. The resonance at the 4p threshold extends over the whole 4p band; it is explained on the basis of electric dipole transitions which involve both spin-orbit splitting and exchange splitting of the 4p states.