Evidence Hub

Retarding moisture-induced chemical degradation of Yttrium Tellurides by tailoring grain boundary chemistry

Jang K, Rahman JU, Yoo SH, Jung C, Woods E, Bueno-Villoro R, Nielsch K, Scheu C et al.

Nature communications, 2026

Abstract

Grain boundary engineering has been extensively applied to improve thermoelectric performance, but its potential to enhance chemical stability remains underexplored. Here, we demonstrate that modifying grain boundary chemistry can effectively suppress the chemical degradation of Y2Te3 under ambient conditions. Scanning transmission electron microscopy and atom probe tomography reveal that H2O preferentially infiltrates along grain boundaries, initiating oxidation of Y2Te3 into Y-O-H phases and causing chemo-mechanical breakdown of the matrix. This process, remarkably, can be retarded by just 1 at.% of Bi incorporation due to its segregation along grain boundaries. Density functional theory calculations reveal the thermodynamic and kinetic origins of Bi segregation, and show how segregated Bi modifies the local electronic and chemical environment of grain boundaries, thereby linking GB chemistry to both chemical stability and thermoelectric performance. These findings establish multifunctional grain boundary engineering as a generalizable strategy for the design of next-generation thermoelectric materials.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free