Element-selective magnetometry in ferrimagnetic erbium iron garnet

The emergence of a field induced canted phase below a critical temperature is one of the characteristic properties of ferrimagnets with two inequivalent antiferromagnetically coupled sublattices. Using x-ray magnetic circular dichroism at the Fe $K$ edge, we have performed element selective magnetometry in ferrimagnetic erbium iron garnet in fields up to 30 T. The signal from the tetrahedral Fe sites at 70 K allows the detection of the two transitions at 10 and 23 T bounding the canted phase and the direct observation of the reversal of the Fe-sublattice magnetization within this phase.