Compositionally modulated $Pbleft(Mg_{rac{1}{3}}Nb_{rac{2}{3}}ight) O_3-xPbTiO_3$ relaxor thin films deposited by pulsed excimer laser ablation technique

摘要

Thin films of $[(1-x)Pbleft(Mg_{rac{1}{3}}Nb_{rac{2}{3}}ight)O_ 3-xPbTiO_3] (x = 0.1 to 0.3)$ (PMN-PT) were deposited on the platinum coated silicon substrate by pulsed excimer laser ablation technique. A template layer of $LaSr_{0.5}Co_{0.5}O_3$ (LSCO) was deposited on platinum substrate prior to the deposition of PMN-PT thin films. The composition and the structure of the films were modulated via proper variation of the deposition parameter such as substrate temperature, laser fluence and thickness of the template layers. We observed the impact of the thickness of LSCO template layer on the orientation of the films. A room temperature dielectric constant varying from 2000 to 4500 was noted for different composition of the films. The dielectric properties of the films were studied over the frequency range of 100 Hz - 100 kHz over a wide range of temperatures. The films exhibited the relaxor-type behavior that was characterized by the frequency dispersion of the temperature of dielectric constant maxima $(T_m)$ and also diffuse phase transition.