Optical bandgap modulation and magnetic characterization of Fe-doped CuCrO2 nanopowders

Using p-type transparent conducting CuCrO2 as a host material, (Cu1−xFex)CrO2 (0 ≤ x ≤ 6 at.%) and Cu(Cr1−yFey)O2 (0 ≤ y ≤ 6 at.%) nanocrystals were prepared by combining solid-state reaction and ball milling. The microstructure, morphology, optical and magnetic properties were characterized by X-ray diffraction, atomic force microscopy, diffuse reflectance spectroscopy and vibrating sample magnetometer. It is found that all the samples have a single CuCrO2 delafossite structure. The variations in lattice constants support the Fe entrance into the Cu and Cr sublattices, respectively, in (Cu1−xFex)CrO2 and Cu(Cr1−yFey)O2. The gradual increase of optical bandgap with the Fe content and the low-temperature ferromagnetism are observed in two series of samples. The present work indicates that Fe-doped CuCrO2 is a dilute magnetic semiconductor and the Curie temperature can be expected to enhance by the optical bandgap modulation.

► The first study on optical bandgap modulation of CuCrO2 by Fe-doping.
► The first study on magnetism of CuCrO2 doped with Fe at the A- and B-sites.
► The optical bandgap is gradually increased with the Fe content.
► Low-temperature ferromagnetism is realized in both series of samples.
► High Curie temperature can be expected to obtain by optical bandgap modulation.