Magnetization process of geometrically frustrated spinel oxide up to an ultra-high magnetic field

We conducted precise magneto-optical Faraday rotation measurements in CdCr2O4and ZnCr2O4up to ultra-high magnetic fields using methods of the single turn coil(up to 190 T) and also the electro-magnetic flux compression(up to 360 T). In CdCr2O4, we have succeeded in observation of the full magnetization process. In ZnCr2O4, we observed magnetization process up to 2.7 μB(the full moment is 3.0 μB). The magnetization processes of both materials were well described by a 4 sub-lattice Heisenberg-spin model including spin-lattice interactions.