Effect of Nonstoichiometry on Dielectric Properties of Strontium Titanate Thin Films Grown by ArF Excimer Laser Ablation

Publisher Website
Google Scholar
Abstract
Dielectric properties and lattice parameters of nonstoichiometric strontium titanate were systematically investigated. The X-ray diffraction measurements indicated the formation of SrO·(SrTiO3) n (n=4-53) instead of SrTiO3 with excess Sr. Epitaxial films grown on (111)Pt/(100)MgO by an ArF excimer laser ablation method were mostly orientated along the (102n+1) axis. With decrease in the frequency of Sr-O plane sliding-in (increasing n value), the dielectric constant ε increased from 87ε0 to 300ε0. Furthermore, an improved property was also obtained in its temperature dependence. The sublattice (perovskite SrTiO3) in the vicinity of sliding-in Sr-O plane was slightly distorted (compressed by about 15%).