Faraday effect in an Ising ferrimagnet in megagauss fields

Abstract Faraday rotation measurements were performed on a Ho 0.7 Y 2.3 Fe 5 O 12 single crystal at 77K and B □[111] in ultrahigh pulsed magnetic fields (up to 350 T). Several anomalies of the rotation were observed in the 15–50 T region, but only a slight increase of the magnitude of the Faraday effect was found above 150 T. A model is proposed to interpret the results, taking into account both the para- and diamagnetic contributions of rare earth and ferrous subsystems.