Structural, microstructure, optical, and electrical properties of Ti-doped CaSnO ₃ prepared by Sol-Gel chemical route

Abstract

Abstract This paper discusses the structural, microstructure, optical and electrical properties of perovskite CaSnO 3 modified by Ti doping. Single phase of Ti-doped CaSnO 3 was obtained using sol-gel method followed by calcination at 750 °C. X-ray diffraction and Fourier transform infrared spectroscopy techniques were used to probe Ti in the samples. Value of lattice parameters of all samples obtained from Rietveld refinement initially decreases with Ti-doping up to CSO5 and then slight increases for CSO7, due to difference in ionic radius between Ti 4+ (0.61 Å) and Sn 4+ (0.69 Å) and surface defect respectively. Using SEM, an average grain size of sintered samples was determined in the range of (0.38–1.02) μ m. Because of the presence of dipole <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo stretchy="false">(</mml:mo> <mml:mi>S</mml:mi> <mml:msub> <mml:msup> <mml:mrow> <mml:mi>n</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> <mml:mo>+</mml:mo> </mml:mrow> </mml:msup> <mml:mrow> <mml:mi>S</mml:mi> <mml:msup> <mml:mrow> <mml:mi>n</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>4</mml:mn> <mml:mo>+</mml:mo> </mml:mrow> </mml:msup> </mml:mrow> </mml:msub> <mml:mo accent="false">″</mml:mo> <mml:mo>/</mml:mo> <mml:mi>T</mml:mi> <mml:msub> <mml:msup> <mml:mrow> <mml:mi>i</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> <mml:mo>+</mml:mo> </mml:mrow> </mml:msup> <mml:mrow> <mml:mi>T</mml:mi> <mml:msup> <mml:mrow> <mml:mi>i</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>4</mml:mn> <mml:mo>+</mml:mo> </mml:mrow> </mml:msup> </mml:mrow> </mml:msub> <mml:mo accent="false">″</mml:mo> <mml:mo>−</mml:mo> <mml:mspace width=".25em"/> <mml:msubsup> <mml:mrow> <mml:mi>V</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>o</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>..</mml:mn> </mml:mrow> </mml:msubsup> <mml:mo stretchy="false">)</mml:mo> </mml:math> at large distances, the dielectric constant and tangent loss of samples was found to be independent of temperatures up to 300 °C, making it a potential candidate for thermally stable capacitor application. Nevertheless, the Arrhenius type conduction mechanism was found to be active in all samples with activation energy (0.41–0.68) eV, indicated that the conduction in samples occurred by transferring electrons between degenerate sites of Sn (Sn 4+ /Sn 3+ /Sn 2+ ) and Ti (Ti 4+ /Ti 3+ /Ti 2+ ). The P-E loop of CSO5 sample shows higher saturation polarization and coercive field than CSO0, making it a potential candidate for memory device application.