Structural and Multiferroic Characteristics of Nanocomposite Ba<SUB>0.5</SUB>Sr<SUB>0.5</SUB>TiO<SUB>3</SUB>-Bi<SUB>0.9</SUB>La<SUB>0.1</SUB>Fe<SUB>0.9</SUB>Mn<SUB>0.1</SUB>O<SUB>3</SUB> Thin Film Heterostructures

Abstract

Multiferroic Ba0.5Sr0.5TiO3/Bi0.9La0.1Fe0.9Mn0.1O3 (BST/BLFM) thin film heterostructures with variable BST to BLFM thickness ratios were directly deposited on p-type Si(100) substrate by a chemical solution deposition method. The X-ray diffraction study revealed that the orientation of BLFM thin films could be varied with the thickness ratio. The thin film heterostructures exhibited low leakage current, large grain size and uniform morphology. The Schottky emission behavior was found to be predominant mechanism for the leakage current. The maximum remanent polarization (Pr = 42.3 C/cm2) was achieved for the heterostructures with thickness ratio of 2.65. The dielectric tunability showed significant tuning response as a function of the thickness ratio and electric field. The BST buffer layer led to increased saturation magnetization (Ms = 28.6 emu/cm3) in BLFM films, which was about 90% larger than that of the Ms value of single layer BLFM films. This result was attributed to the interface ferromagnetic exchange interaction that was confirmed by magnetoelectric measurements.