Vertically aligned nanocomposite (BaTiO3)0.8 : (La0.7Sr0.3MnO3)0.2 thin films with anisotropic multifunctionalities

Abstract

A new two-phase BaTiO₃ : La_0.7Sr_0.3MnO₃ nanocomposite system with a molar ratio of 8 : 2 has been grown on single crystal SrTiO₃ (001) substrates using a one-step pulsed laser deposition technique. Vertically aligned nanocomposite thin films with ultra-thin La_0.7Sr_0.3MnO₃ pillars embedded in the BaTiO₃ matrix have been obtained and the geometry of the pillars varies with deposition frequency. The room temperature multiferroic properties, including ferromagnetism and ferroelectricity, have been demonstrated. Anisotropic ferromagnetism and dielectric constants have been observed, which can be tuned by deposition frequencies. The tunable anisotropic optical properties originated from the conducting pillars in the dielectric matrix structure, which cause different electron transport paths. In addition, tunable band gaps have been discovered in the nanocomposites. This multiferroic and anisotropic system has shown its great potentials towards multiferroics and non-linear optics.