Spin-Wave Resonance in Magnetic Semiconductor Thin Films - Experiment

Abstract

Magnetic properties of polycrystalline thin films of chromium chalcogenide spinels (CdCr2Se 4 lightly doped with indium and CdCr2xIn2-2xSe4) were studied. The ferromagnetic (FMR) and spin-wave resonance (SWR) techniques were used to investigate the temperature dependences of both the spin-wave stiffness constant D and the saturation magnetization Ms . The resonance spectra were recorded in the temperature range extending from 4.2 K to 300 K. The influence of indium concentration on M s (T) and D(T) was studied. It was shown that lightly doped samples (In/Cd < 1% at.) exhibited the ferromagnetic ordering with Ms (T) and D(T) being the linear functions of T3 /2 and T512 , respectively. Higher concentration of indium produced the reentrant transition and spin-glass state of magnetic ordering in CdCr2 x In2-2xSe4. The temperature dependence of M. was also found from the FMR data for these two magnetic phases.