FTIR and dielectric studies of nickel doped potassium hexa-titanate (K_2Ti_6O_(13)) fine ceramics

摘要

The dielectric and electrical properties such as relative permittivity (ε'), loss tangent (tanδ), and ac conductivity (σ_(ac)) have been studied in the temperature range 373-773 K at three different frequencies 100, 200, 400 kHz for doped potassium hexa-titanate (K_2Ti_6O_(13)) samples. It was observed that dielectric constant and loss tangent decreases while ac conductivity increases with the increase in frequency. The temperature dependent relative permittivity showed a phase transition for all samples. Dielectric loss mechanism was observed to include space charge polarization and dipole orientation. Moreover, electron-hopping conduction was observed to be dominant in the low temperature region, whereas intratunnel ionic conduction prevailed at higher temperatures. Fourier transform infrared spectroscopy analysis was also carried out to identify the chemical bonds present in the specimens.