Comparative study on aging effect in BiFeO3 thin films substituted at A- and B-site

TL;DR

This study compares aging effects in BiFeO3 thin films substituted at A- and B-sites, revealing differences in hysteresis behavior, leakage current, and dielectric properties linked to defect chemistry and crystal structure.

Contribution

It provides a comparative analysis of aging effects in A-site and B-site substituted BiFeO3 films, highlighting the influence of defect states and structural factors.

Findings

BFNO shows less constrained double hysteresis loops at higher voltages

BFNO exhibits lower leakage current and dielectric constant

Aging effects are linked to defect chemistry and crystal structure

Abstract

Typical characteristics of aging effect, double hysteresis loops, were observed in (100)-oriented Bi0.95Ca0.05FeO3 (BCFO) and BiFe0.95Ni0.05O3 (BFNO) films grown on LaNiO3(100)/Si substrates. The double hysteresis loops for BCFO film become less "constrained" with increasing applied voltage compared to that for BFNO, indicating that the aging effect is more severe in the latter. This can be demonstrated by the lower leakage current and smaller dielectric constant for BFNO. These phenomena are explained based on the crystal structure and defect chemistry. The defect states of the Bi, Ca, Fe, Ni and O ions were clarified by the XPS data.