Fig. 3
From: A series of magnon crystals appearing under ultrahigh magnetic fields in a kagomé antiferromagnet
Magnetization measurements by the Faraday rotation technique in pulsed magnetic fields up to 160 T. a Single crystal of CdK on a sapphire disk substrate used in high-field Faraday rotation measurements. The crystal exhibits a flat (001) surface that effectively reduces scattering of light and is sufficiently large to obtain a Faraday rotation signal. b Schematic illustration of the experimental set-up. A high-magnetic field is generated inside a single-turn coil of 12 mm inner diameter by injecting a huge electric current (2–3 mega-ampere). c Typical time evolutions of a pulsed magnetic field with a maximum at 160 T and a time duration of 7 µs and Ip and Is at 5 K. The hexagonal plate-like single crystal of CdK shown in a mounted on a sapphire substrate is placed in the coil such that the magnetic field is perpendicular to the hexagonal surface (B /// c). Linearly polarized incident light comes from the left and passes through the crystal. A change in the polarization angle due to the Faraday effect in the magnetized crystal is measured: transmitted light is split into vertical and horizontal components, Ip and Is, and each intensity is recorded by an oscilloscope. d Field dependences of the Faraday rotation angle θF and the corresponding magnetizations at 5 K (purple), 6 K (yellow), and 8 K (blue-green). For clarity, offsets of 20 and 50 degrees are added to the data at 6 and 8 K, respectively. The magnetization data from the Faraday rotation angle are calibrated to reproduce those obtained by the induction method by using a nondestructive pulse magnet as denoted by the black line below 55 T at 4.2 K. The large noises at approximately 30 T in the data at 6 and 8 K and at approximately 50 T in the data at 5 K are due to reductions in intensity for either Ip or Is at the rotation angle corresponding to 90 degree
