DOPANT EFFECTS ON THE STRUCTURAL, OPTICAL AND ELECTRICAL TRANSPORT PROPERTIES IN SrTi_(1-x)Co_xO_3 NANOPARTICLES SYNTHESIZED BY SOL–GEL METHOD

摘要

We investigate effects of Co dopant concentration on the structure, as well as optical and electrical transport properties in SrTi_(1-x)Co_xO_3 (x = 0.00, 0.10, 0.20, 0.30, 0.40, 0.50) nanoparticles prepared by sol–gel method with annealing temperature considerably lower than that employed conventionally. The dopant-induced changes are studied by XRD, Raman, Optical absorption and Impedance measurements. The results show an average particle size of about 30 nm, and decreasing lattice parameters. In the Raman spectra, a broad structure in the region 200–500 cm~(-1) is almost absent and the peaks in the region 600–800 cm~(-1) show different relative weights with respect to those from SrTiO_3, which is related to structural changes, decreasing gap with increasing dopant concentration in conjuction with increasing grain boundary contribution to the impedance. These results also demonstrate the feasibility of synthesizing the compound with low annealing temperature.