High-dielectric-tunability of ferroelectric (Pb, Sr)TiO3 thin films on (001) LaAlO3

Ferroelectric (Pb,Sr)TiO3 (PSTO) thin films were epitaxially grown on (001) LaAlO3 (LAO) by using pulsed laser deposition. 'Microstructural characterizations with x-ray diffraction and transmission electron microscopy indicate that the as-grown films have excellent single crystalline quality and a (001)(PSTO)//(001)(LAO) and [100](PSTO)//[100](LAO) interface relationship. Dielectric property measurements reveal that the as-grow films have a very high dielectric constant value of 3100 and very large dielectric tunability of 48% at 40 V/cm at room temperature. These excellent results suggest that the highly epitaxial ferroelectric (Pb, Sr)TiO3 thin films can be developed for room-temperature tunable microwave elements in wireless communication applications. (C) 2004 American Institute of Physics.