Structural and dielectric characterizations of PST(Pb0.8Sr0.2)O-3/PST(Pb0.2Sr0.8)O-3 heterolayered thin films

Abstract

Dielectric (Pb0.8Sr0.2)O-3 (PST (80/20)) / (Pb0.2Sr0.8)O-3 (PST (20/80)) heterolayered thin-film structures were fabricated by a spin-coating method on Pt/Ti/SiO2/Si substrate by alternately using PST (20/80) and PST (80/20) alkoxide solution. The structure and the morphology of the films were analyzed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The PST heterolayered thin films exhibited strong (10 0) orientation. It can be assumed that the lower PST layer forms a nucleation site or a seeding layer for the formation of the upper PST layer. The dielectric constant, dielectric loss, and tunability of the PST-6 heterolayered structure measured at 100 kHz were 452.2, 0.021 and 41 %, respectively. All these parameters showed an increase with an increasing number of coatings, due to an increase in the strong (100) orientation.