Mal. Nobre et S. Lanfredi, Impedance spectroscopy analysis of high-temperature phase transitions in sodium lithium niobate ceramics, J PHYS-COND, 12(35), 2000, pp. 7833-7841
An investigation was made of the sodium lithiumniobate Na0.85Li0.15NbO3 cer
amics using permittivity properties. Permittivity measurements were carried
out by impedance spectroscopy in a frequency range of 5 to 1.3 x 10(7) Hz
and at temperatures ranging from 25 to 750 degrees C. The thermal stability
of the dielectric behaviour was evaluated as a function of several thermal
cycles. The permittivity response was found to depend on both the partial
thermal cycle (heating or cooling cycle) and the number of cycles. Three ph
ase transitions are proposed based on a maximum of permittivity response as
a function of temperature. The dielectric behaviour and its relationship w
ith the phase transition phenomenon are discussed.