Structural and optical characterization of samarium doped yttrium oxide nanoparticles.

Here we demonstrate the preparation of samarium doped yttrium oxide nanoparticles using samarium chloride as a samarium source by co-precipitation method. The samarium doped yttria nanoparticles are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and Fourier transform infra-red spectroscopy (FT-IR). The XRD results revealed that all the synthesized samples exhibit cubic phase with average grain size of the nanoparticles in the order of 9-20 nm, calculated by Scherer's formula. The strain present in the annealed sample is estimated from Williamson-Hall (W-H) plot which is in the order of 3 x 10(-3). SEM and HRTEM results showed that the samples are composed of aggregated nanoparticles with uniform shape and size. The particles are highly crystalline which is also confirmed by XRD results. The position of the absorption peak is shifted towards the lower wavelength side when particles sizes reduced around 10 nm is observed by UV-visible (UV-vis) spectrometer. The direct band gap is estimated from UV-vis absorption spectrum, the calculated value is 5.98 and 5.87 eV for as-prepared and annealed sample (800 degrees C) respectively. The high intense red emission band observed at 608 nm from 4G(5/2)-6H(7/2) transition for Y2O3:Sm3+ under excitation at 214 nm using fluorescence spectrometer.