Study of the structural and optical properties of nanoparticles of Pr_(1-x)Sr_xMnO_3 (x = 0.1, 0.2, 0.3, 0.4 and 0.5) obtained by a modified polymer complex method

摘要

In this work, ceramic powders of the Pr_(1-x)Sr_xMnO_3 (x = 0.1, 0.2, 0.3, 0.4 and 0.5) were obtained. The synthesis process used in obtaining the powders was the polymer complex method - Pechini. The nanoparticles were synthesized at 900°C. Their structural and optical characteristics were determined using infrared (IR), Ultraviolet-Visible diffuse reflectance spectroscopy (UV-DRS), and X-ray diffraction (XRD), and scanning electron microscopy (SEM). The synthesized powders showed an orthorhombic perovskite-type structure, with a primary particle size of ＜100nm, and a gap energy between ～1.5 5eV and 1.61 eV. By increasing the content of strontium in the samples, a decrease in crystallite size was observed, with a minimum value for the Pr_(0.5)Sr_(0.5)MnO_3 sample (18.8 Å). Considering the nature of the synthesis process used, a mechanism was proposed to explanation of the formation of nanoparticles.