Low temperature and magnetic field dependent ferroelectric behaviour of four-layered Aurivillius Bi5FeTi3O15 film prepared by spin coating

Abstract

Thin films of four–layered Aurivillius Bi5FeTi3O15 compound were prepared using spin coating method. Phase purity of the sample is confirmed via X–ray diffraction and Raman spectroscopy measurements. Ferroelectricity in the prepared film is established from polarization versus electric field (P–E) loop measurements. The remnant and saturation polarization obtained from low temperature P–E measurements reveal a peculiar temperature dependence viz., decreasing on lowering the temperature. Apart from this, a development of an internal field in the system is observed towards lower temperatures which is reflected as biasing in the loops. Further, temperature dependent leakage current measurements have been performed and the analysis into conduction mechanisms shed light into the possible defect related mechanisms responsible for the aforementioned peculiar low temperature ferroelectric behavior. Also, the possibility of multiferroicity in the prepared film is explored with external magnetic field dependent P–E measurements and the results show very weak coupling between polarization and magnetic field.