D. Zając

EXAFS study of indium doped magnetic semiconductor CdCr2Se4

An EXAFS study of indium substituted CdCr2Se4 magnetic semiconductors is presented. Thin films of the compositions Cd1−yCr2−2xIny+2xSe4 with 2x=0.00, 0.11, 0.27 and y=0.14, 0.11, 0.00, respectively, were prepared by the radio frequency (RF) sputtering technique. From the Cr–K edge and Se–K edge EXAFS spectra the information on the local atomic environments around Se and Cr sites was obtained. With indium substitution the second nearest neighbour shell of the Cr site, which consists of Cr and possibly In ions, splits into two shells. The splitting increases with the increasing amount of indium. Direct current magnetisation measurements have shown that the samples with y=0 or x=0 are in the spin glass state and the samples with x≠0 and y≠0 are in the randomly canted state. These changes of magnetic properties are attributed to the differences of local environments as observed in the EXAFS measurements.