Fabrication of BiFeO3 capacitor structures with reduced leakage current

Abstract

Multi layered metal-insulator-metal (MIM) structures with BiFeO3 (BFO) and Ba0.25Sr0.75TiO3 (BST) thin films were fabricated by chemical solution deposition. Crystalline structure of BFO was recognized as rhombohedral and was not influenced by the BST intermediate layer. Compared to the homogenous BFO, in the heterostructures, coercivity increased and saturation magnetization reduced. BST intermediate layer between the substrate and BFO layer resulted in the leakage current reduction by 3 orders of magnitude. The frequency and temperature dependent dielectric properties showed space charge accumulation between the layer of BST and BFO, and hence Maxwell-Wagner type dispersion.