Thickness-Dependent Electrical Characteristics of Sputtered BFO Thin Films over Wide Temperature Range

This study explores how thickness and grain size impact leakage current in RF-sputtered BFO thin films. Morphology reveals that increasing film thickness leads to larger grains, boosting grain resistivity by altering oxygen vacancies, thus reducing leakage current. Pt/Ti/BFO/FTO capacitive heterostructures are examined at varied temperatures, demonstrating a positive temperature coefficient of resistance effect. This effect stems from the closely linked interaction between multiferroic BFO and highly conductive oxide FTO, and potentially forming an electrical double layer at the Pt/Ti/BFO interface. Additionally, a dominant modified Space Charge Limited Current conduction mechanism is observed in Pt/Ti/BFO/FTO capacitive heterostructures under varying electric fields.