Characteristics of (Pb,Sr)TiO3 thin films with various Sr content

(Pb1−x,Srx)TiO3 (PST) thin films with various Sr content (x=0.2, 0.4, and 0.6) were fabricated on Pt/Ti/SiO2/Si substrates by radio frequency magnetron sputtering. With the increase of Sr content, the structure of PST films changed from tetragonal to cubic symmetry and the grain size slightly decreased. Dielectric and ferroelectric properties were highly depended on the composition of PST films. PST (x=0.2) films showed a good polarization-switching characteristic with a relatively lower dielectric constant. PST (x=0.6) films displayed the excellent tunable dielectric property with a low loss tangent and performed well on the insulating characteristic. These results illustrated that PST thin films with a suitable composition have potential for applications in nonvolatile ferroelectric random access memory, dynamic random access memory and tunable devices.