The Electrical and Microstructural Properties of Zr-doped LaNbO sub(4) Thin Ceramic Films

In the current research thin Zr-doped lanthanum niobium oxide (LaNb sub(1-x)Zr sub(x)O sub(4)) films deposited by magnetron sputtering were studied to investigate their microstructural and electrical properties. The main attention is paid to the electrical processes in the formed thin films, e.g. relaxation time and activation energy derived from the different electrical parameters. X-ray diffractometry, energy-dispersive X-ray spectroscopy and scanning electron microscopy were used to study the structure and composition of the films. Electrical parameters of LaNb sub(1-x)Zr sub(x)O sub(4) thin ceramic were investigated by impedance spectroscopy in the frequency range from 0.1 Hz to 1.0 MHz in temperature range from 773 to 1173 K. It is shown that LaNb sub(1-x)Zr sub(x)O sub(4) thin ceramic films have nanocrystalline structure with characteristic peaks corresponding to the tetragonal LaNbO sub(4) structure. The increase of Zr dopants does not influence the tetragonal structure. It was revealed that the Non-Debye relaxation process is dominant in the formed thin films and the activation energy is dependent on the concentration of the dopants. The comparison between the activation energies estimated using different electrical parameters: electrical modulus, impedance imaginary part and slope from the conductivity plot was made. Also the relaxation time was calculated. The relaxation time varies from from 2.80 times 10 super(-4) s to 3.78 times 10 super(-5) s in the formed thin films.