Structural, optical and magnetic properties of Mn2+ doped ZnO-CdS composite nanopowder

•Mn2+ doped ZnO-CdS composite synthesized by simple chemical precipitation method.•Hexagonal phase identified for both ZnO and CdS.•Spherical and sphere like structures were observed in TEM micrographs.•Mn2+ doped sample emits orange-red light.•Prepared sample exhibited room temperature ferromagnetism.

Chemical precipitation method was used for the synthesis of Mn2+ doped ZnO-CdS composite nanopowder. The effect of Mn2+ doping was investigated on their structural, optical and magnetic properties. XRD pattern reveals the hexagonal phase of ZnO as well as CdS and the average crystallite size is found to be 18 nm. The morphological studies show non-uniformly distributed spherical like structures with little agglomeration. Crystal field and interelectronic repulsion parameters are evaluated from optical absorption study. EPR spectrum exhibits a well resolved sextet at g = 1.9924. By correlating optical and EPR studies, Mn2+ ions occupy octahedral sites in the host lattice which is also confirmed by PL analysis. From 1931 CIE chromaticity diagram, the prepared sample exhibits orange-red emission. IR spectrum confirms the existence of Zn-O and Cd-S vibrational modes. Room temperature ferromagnetism is observed in the prepared sample.

Graphical abstractPL spectrum of Mn2+ doped ZnO-CdS composite nanopowder is recorded at room temperature under the excitation wavelength of 325 nm. The spectrum exhibits four characteristic bands at UV, blue, green and red regions. The sharp red emission band at 627 nm is due to the incorporation of Mn2+ ions. The emission process is attributed to the transition from lowest excited state to ground state, 4T1 → 6A1, is arising from the octahedrally coordinated Mn2+ sites. CIE chromaticity coordinates are also calculated from the corresponding PL spectrum as (x, y) = (0.460, 0.379), which represents orange-red emission.Figure optionsDownload full-size imageDownload as PowerPoint slide