Stress induced ferroelectricity of homoepitaxally grown SrTiO₃ thin films prepared by pulsed laser deposition in the magnetic field (Dynamic-Aurora PLD)

Abstract

We prepared homoepitaxial SrTiO3 thin films on Nb-SrTiO3(Nb:0.5wt%) substrate by Dynamic-Aurora pulsed laser deposition. SrTiO3 films deposited in the magnetic field of 2000 G showed ferroelectricity. The composition of films deposited on Si (001) substrate measured by x-ray fluorescence analysis revealed that the film is Sr-rich composition (Sr/Ti = 1.4). However, other films prepared by various condition did not show ferroelectricity. Therefore it was clarified that both Sr-rich composition and in-situ magnetic field during deposition is needed to achieve ferroelectiricity. Temperature dependency of dielectric constant of the film revealed that the film has dielectric peak at around 420 ºC.