Structural and dielectric properties of Li_2O-doped TiO_2

摘要

The dielectric properties of the system Li-Ti-O have been exploited in the frequency range 20 Hz-1 MHz in order to obtain permittivity data of materials having high-κ' and low loss. Doping of titanium dioxide with lithium oxide acts as a strong promoter of the anatase to rutile phase transition and it may reduce the phase transition temperature (915 deg C) by more than 100 deg C, possibly due to induced oxygen concentration disorders in the ternary Li-Ti-O system. For TiO_2:Li_2O molar ratios of 98.92:1.08 and calcination temperature of 950 deg C the resulting material exhibits high-K' and low-loss permittivity properties with lack of interfacial polarization effects. Its dielectric response is superior compared to pure (undoped) rutile as obtained by calcination at much higher temperatures (1180 deg C).