CRYSTALLOGRAPHIC, MORPHOLOGICAL AND W-H MODELS INVESTIGATIONS ON Mn SUBSTITUTED ZnO NANOCRYSTALS

Mn doped ZnO nanocrystals were prepared by co-precipitation route sintered at 450 °C temperature. XRD results indicate that the samples having hexagonal (wurtzite) structure. From X-ray data it is found that the lattice parameters increase with increasing Mn concentration. The X-ray density decreases with increasing Mn concentration of Zn 1-x Mnx O nanocrystals. It indicates that the Mn ions go into the Zn site in the ZnO lattice structure. TEM results reveal that the pure and Mn substituted ZnO samples are spherical in shape with average particle size about 20-60 nm. The crystalline size and lattice strain were evaluated by Williamson-Hall (W-H) analysis using X-ray peak broadening data. All other relevant physical parameters such as strain, stress and energy density were calculated by the different models Viz, uniform deformation model (UDM), uniform deformation stress model (UDSM) and Uniform deformation energy density model (UDEDM) considering the Williamson-Hall analysis. These models reveal different strain values it may be due to the anisotropic nature of the material. It is found that the mean particle size of Zn 1-x MnxO nanoparticles was estimated from TEM analysis, Scherrer’s formula & W-H analysis is highly comparable.