Grain boundary structural transformation induced by co-segregation of aliovalent dopants.

ABSTRACT: Impurity doping is a conventional but one of the most effective ways to control the functional properties of materials. In insulating materials, the dopant solubility limit is considerably low in general, and the dopants often segregate to grain boundaries (GBs) in polycrystals, which significantly alter their entire properties. However, detailed mechanisms on how dopant atoms form structures at GBs and change their properties remain a matter of conjecture. Here, we show GB structural transformation in α-Al₂O₃ induced by co-segregation of Ca and Si aliovalent dopants using atomic-resolution scanning transmission electron microscopy combined with density functional theory calculations. To accommodate large-sized Ca ions at the GB core, the pristine GB atomic structure

SUBMITTER: Futazuka T 

PROVIDER: S-EPMC9477882 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature