Anomalous electronic, phonon, and spin excitations in the chalcogenide spinel FeCr2S4

摘要

We report inelastic light scattering experiments on FeCr2S4, which shows colossal magnetoresistance (CMR) effects around TC≈170 K. Several distinct features have been observed: (i) anomalies in phonon frequencies and linewidths around TC, (ii) the vanishing of one-magnon excitation close to 0.83 TC, and (iii) the presence of an electronic background at low temperature. This highlights the significance of an intricate interplay among electron, spin, orbital, and lattice degrees of freedom in inducing CMR effects.