Spin-lattice instability in the chromium sulfur spinel Fe0.5Cu0.5Cr2S4

摘要: Zero field ?SR spectroscopy was applied to a polycrystalline sample of the ferrimagnetic sulfur spinel Fe0.5Cu0.5Cr2S4 between?5 and 315?K. The temperature dependence interstitial magnetic B? as well transverse longitudinal relaxation rates were deduced. At around 100?K, exhibits strong deviation from expected Brillouin-like behavior together with maximum rate. These features are characteristic for spin reorientation transition. This instability spin-lattice has not been reported previously. 57Fe M?ssbauer data same show no irregularity in Fe hyperfine which could indicate that involves primarily Cr sublattice. Above below regime, disorder is sizable, but excessive. low temperatures, spins essentially static, dynamics sets above range. also complemented by new susceptibility magnetization taken on similar material.