Changes in structural, optical and magnetic properties of nano-CuS upon doping with Mn and Fe: a comparative study

Abstract

Nano-CuS doped with Mn or Fe (Cu1–x(Mn or Fe)xS; 0 ≤ x ≤ 0.2) was prepared by a thermolysis method. The structural, optical and magnetic properties were investigated using XRD synchrotron radiation, scanning electron microscope (SEM), ultraviolet spectroscopy (UV–Vis), photoluminescence (PL) and vibrating sample magnetometer (VSM). Diffraction patterns manifested a single phase of CuS hexagonal structure with a minor phase Cu2S in case of Fe doped and only a single phase in case of Mn-doped CuS samples. Analysis indicated a necessity of good diffraction patterns and Rietveld analysis for phase’s determination. The changes in bond lengths, lattice parameters, and microstrain were determined by Rietveld method and correlated with the measured physical properties. Energy gaps showed an irregular change with increased amount of Mn doped while they exhibited a regular decrease as the amount of Fe increased in CuS matrix. The PL emissions revealed three sub-violet, (two violet, one blue) and (two violet, one blue, one green) emitted peaks for pure, Mn- and Fe-doped CuS, respectively. The PL intensity was enhanced for x = 0.1 doped Mn or Fe then it quenched by further doped. Bare CuS showed diamagnetic properties; while Mn- and Fe-doped samples had paramagnetic properties.