Observation of the effects of Bi-deficiency on ferroelectric and electrical properties in Bi(1+x)FeO3/La0.65Sr0.35MnO3 heterostructures via atomic force microscopy

Abstract

Bi_(1+x)FeO₃ thin films with different Bi contents (x = 0%, 5%, and 10%) were grown on (001) SrTiO₃ substrates with La_0.65Sr_0.35MnO₃ (LSMO) buffered layers via pulsed laser deposition. The effects of Bi deficiencies on the ferroelectric and electrical properties of Bi_(1+x)FeO₃/LSMO heterostructures are distinguished and investigated using various advanced and powerful techniques based on atomic force microscopy (piezoresponse force microscopy, electric force microscopy, surface Kelvin probe force microscopy and conductive atomic force microscopy). The results show an enhancement in ferroelectric properties, an improvement in electrical properties and a decrease in conductivity of Bi_(1+x)FeO₃ thin films with decreasing Bi deficiencies; these could be explained by the changes in interfacial interaction and energy bands. The investigations could pave a way to improving the Bi_(1+x)FeO₃ films' performance by controlling Bi deficiencies.