Influence of indium dilution level on magnetic properties and photoconductivity of Cd1-yCr2-2xIn2x+ySe4 magnetic semiconductors

Magnetic semiconductors of CdCr2Se4 diluted by indium belong to the class of soft magnetic materials. The amount of indium alters the energetic structure of chalcogenide spinel. For CdCr2Se4:In magnetic semiconductor the state with reentrant transition (REE) is achieved. In the case of Cd1-yCr2-2xIn2x+ySe4 dilution, the spin glass (SG) state and randomly canted state is obtained. Chalcogenide spinel could be used as the element of a near-infrared detector. Then the photoconductivity properties - the voltage sensitivity versus the light wavelength - are of interest. This parameter is also affected by the dilution level. The polycrystalline Cd1-yCr2-2xIn2x+ySe4 thin films obtained by rf-sputtering technique were studied. It was found that the dependence of voltage sensitivity of the photoresponse on the wavelength differs significantly for samples with REE and in the SG state. For both types of magnetic ordering, the photoresponse below the critical magnetic temperature is larger than above it. (author)