Study on Structural and Dielectric Properties of (Ti, Cr) Co-doped SnO 2 Nanoparticles

The present study deals with the impact of (Ti, Cr) co-doping on the structural, optical, and dielectric properties of the SnO₂ nanoparticles. The traditional solid-state reaction route is adopted to prepare undoped, Ti-doped and (Ti, Cr) co-doped SnO₂ nanoparticles. The structural analysis revealed the polycrystalline nature with a single phase of tetragonal rutile type structure for all the prepared samples. The increment in the crystallite size is observed with doping. The Scanning electron microscopy showed that the nanoparticles are spherical and uniformly distributed. A small variation is noticed in the optical band gap energy of doped samples as compared to the undoped SnO₂. The significant changes have been reported in parameters such as dielectric function, capacitance, dielectric loss factor, and AC conductivity. Maxwell-Wagner model is suitable to illustrate the decreasing behaviour of dielectric constant and dielectric loss with frequency. Ti and Cr co-doped SnO₂ nanoparticles revealed lower dielectric loss contrary to Ti-doped and undoped SnO₂ nanoparticles. The ac conductivity of all the prepared samples increases with frequency and doping. Ti-doped SnO₂nanoparticles exhibited higher ac conductivity, which can be explained by the hopping of charge carriers.