Annealing effects on the structural and dielectric properties of (Nb + In) co-doped rutile TiO2 ceramics

摘要

Density functional theory calculations were conducted to investigate the electronic structures of rutile Ti _(16) O _(32) , Ti _(13) Nb _(2) InO _(32) , and Ti _(13) Nb _(2) InO _(31) systems. High density (Nb + In) co-doped rutile TiO _(2) ceramics were successfully prepared by one modified solid state method. XRD, XPS, Raman scattering and FT-IR measurements were performed to investigate the structural properties of the (Nb + In) co-doped rutile TiO _(2) ceramics annealed in different atmospheres. The lattice parameters for the (Nb + In) co-doped rutile TiO _(2) ceramics were enlarged slightly after they were annealed in air and oxygen. Raman scattering results indicate that the E _(g) modes are quite sensitive to oxygen vacancy in comparison with the other Raman active modes. The ceramics annealed in oxygen at 873 K exhibit the best dielectric performance with giant dielectric permittivity (>14?000) and small dielectric loss (<0.2) over the frequency range from 40 Hz to 1 MHz.