A New Line Defect in NdTiO3 Perovskite

TL;DR

This paper reports the discovery and characterization of a novel line defect in NdTiO3 perovskite, revealing unique atomic and electronic structures with potential for engineering new electronic properties.

Contribution

The study identifies and characterizes a previously unknown line defect in NdTiO3, combining STEM imaging and ab initio calculations to reveal its atomic structure and electronic implications.

Findings

Detected a new line defect appearing as a rotated perovskite cell in STEM images.

The defect involves Ti-O vacancy lines and Nd columns with Ti4+ ions.

The defect's Ti valence suggests potential for engineered electronic properties.

Abstract

Perovskite oxides form an eclectic class of materials owing to their structural flexibility in accommodating cations of different sizes and valences. They host well known point and planar defects, but so far no line defect has been identified other than dislocations. Using analytical scanning transmission electron microscopy (STEM) and ab initio calculations we have detected and characterized the atomic and electronic structures of a novel line defect in NdTiO3 perovskite. It appears in STEM images as a perovskite cell rotated by 45 degrees. It consists of self-organized Ti-O vacancy lines replaced by Nd columns surrounding a central Ti-O octahedral chain containing Ti4+ ions, as opposed to Ti3+ in the host. The distinct Ti valence in this line defect introduces the possibility of engineering exotic conducting properties in a single preferred direction and tailoring novel desirable functionalities in this Mott insulator.