Elucidation of crystal and electronic structures within highly strained BiFeO3

April 2017

by In-Tae Bae, András Kovács, Hong Jian Zhao, Jorge Íñiguez, Shintaro Yasui, Tomohiro Ichinose and Hiroshi Naganuma

Crystal and electronic structures of ~380 nm BiFeO3 film grown on LaAlO3 substrate are comprehensively studied using advanced transmission electron microscopy (TEM) technique combined with first-principles theory.

Cross-sectional TEM images reveal the BiFeO3 film consists of two zones with different crystal structures. While zone II turns out to have rhombohedral BiFeO3, the crystal structure of zone I matches none of BiFeO3 phases reported experimentally or predicted theoretically.

Detailed electron diffraction analysis combined with first-principles calculation allows us to determine that zone I displays an orthorhombic-like monoclinic structure with space group of Cm (=8). The growth mechanism and electronic structure in zone I are further discussed in comparison with those of zone II.

This study is the first to provide an experimentally validated complete crystallographic detail of a highly strained BiFeO3 that includes the lattice parameter as well as the basis atom locations in the unit cell.

Further reading:

In-Tae Bae, András Kovács, Hong Jian Zhao, Jorge Íñiguez, Shintaro Yasui, Tomohiro Ichinose and Hiroshi Naganuma:
Elucidation of crystal and electronic structures within highly strained BiFeO3 by transmission electron microscopy and first-principles simulation,
Scientific Reports 7 (2017) 46498