Thin films of Pb1-xLax(Zr0.65Ti0.35)1-x/4O3 with x=0.09 (PLZT 9/65/35) have been grown by pulsed laser deposition (PLD) and by PLD assisted by radio frequency (RF) discharge in oxygen which increases the plasma reactivity and reduces the oxygen vacancies in films and at the film-bottom electrode interface. Significant compositional, structural and dielectric differences have been found among samples grown in the same deposition conditions excepting for RF power. Films grown by RF-assisted PLD have less pyrochlore and are more oriented. For these films dielectric permittivity vs. temperature variation was typical of relaxor ferroelectrics and the temperature of the dielectric maximum was close to that obtained in bulk, but the permittivity value was much lower. This was attributed mainly to the influence of a low permittivity interface layer and to the detrimental effect of pyrochlore phase, still present in small quantities even in the films obtained by RF-PLD. The dielectric behavior of films grown without RF discharge was very different: no dielectric anomaly was observed, only a step increase above 180 °C. Moreover much higher dielectric loss was measured for these films.
Synthesis and characterization of PLZT thin films obtained by pulsed laser deposition
P Verardi;
2004
Abstract
Thin films of Pb1-xLax(Zr0.65Ti0.35)1-x/4O3 with x=0.09 (PLZT 9/65/35) have been grown by pulsed laser deposition (PLD) and by PLD assisted by radio frequency (RF) discharge in oxygen which increases the plasma reactivity and reduces the oxygen vacancies in films and at the film-bottom electrode interface. Significant compositional, structural and dielectric differences have been found among samples grown in the same deposition conditions excepting for RF power. Films grown by RF-assisted PLD have less pyrochlore and are more oriented. For these films dielectric permittivity vs. temperature variation was typical of relaxor ferroelectrics and the temperature of the dielectric maximum was close to that obtained in bulk, but the permittivity value was much lower. This was attributed mainly to the influence of a low permittivity interface layer and to the detrimental effect of pyrochlore phase, still present in small quantities even in the films obtained by RF-PLD. The dielectric behavior of films grown without RF discharge was very different: no dielectric anomaly was observed, only a step increase above 180 °C. Moreover much higher dielectric loss was measured for these films.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
