Abstract
Single crystals of the Cd~1‐x~Fe~x~In~2~S~4~ compounds were grown by the chemical vapour transport method using iodine as transport agent. The crystals were grown by placing the ampoule in a two zone furnace, keeping the source temperature and the deposition temperature at 850 and 800 °C respectively. The resulting crystals with nominal concentrations: x = 0.25, 0.5, 0.75 were characterized by X‐ray powder diffraction, electron probe micro‐analysis and magnetic measurements. Electron probe micro‐analysis showed that the actual concentration of Fe was lower than the nominal one. X‐ray diffractograms were taken at room temperature for each sample, revealing that the compounds form a solid solution in the whole range of compositions and crystallize with cubic symmetry in the space group Fd3m. All samples show a spinel structure with a random arrangement of cations. The magnetic behavior of the samples was investigated by low‐field magnetization measurements in the range 5‐300 K. The observed magnetic behavior does not show any magnetic transition in the studied temperature range. However an irreversibility has been observed between zero‐field‐cooled (ZFC) and field‐cooled (FC) cycles. High temperature susceptibility data follow the Curie‐Weiss law with a negative paramagnetic Curie temperature, indicating the predominance of antiferromagnetic interactions. The optical absorption data for sample with x = 0.75 shows a direct energy gap of 1.28 eV at RT. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)