Production and Characterization of Magnesium-Doped Copper Chromite Fibers

In this study, Mg-doped CuCr1-xMgxO2 (x=0, 0.01, 0.03, 0.05) fibers are synthesized via electrospinning process followed by a two-step heat treatment in air and Ar atmospheres. The produced samples are all crystalline with a fiber diameter ranging from 120 to 140nm. The effect of Mg2+ substitution for Cr3+ on the structural, morphological, and optical properties of CuCrO2 fibers is investigated systematically. Structural characterizations indicate that the solubility limit of Mg2+ is around 3at.% and beyond this concentration the formation of MgO phase is observed. This also leads to the formation of Cu cations with ((+)2) oxidation state. In addition, the incorporation of Mg into the CuCrO2 lattice hinders the formation of perfect hexagonal-shaped isolated grains and contribute to the preservation of fiber morphology after the final sintering step. Further, the optical transmittance in the visible range decreases with increasing Mg-doping ratio. The corresponding optical band gaps are determined to be 3.53, 3.47, 3.30, and 3.22eV, respectively, for x=0, 0.01, 0.03, 0.05.