Strain-oxygen vacancies coupling in topotactic (La,Sr)CoO3-δ thin films
Year: 2024
Type: article
Abstract: Oxygen defect engineering is a widely used approach for tuning physical properties in oxides. Multivalent transition metal oxide La0.7Sr0.3CoO3-δ (LSCO) shows oxygen vacancy-driven metal-to-insulator transition (MIT) due to topotactic phase transition and its high oxygen vacancy tolerance. Here, we introduce strain as a new degree of freedom to study the strain-oxygen vacancy coupling effects and elucidate its impact on the electronic property in oxygen-deficient LSCO epitaxial thin films grown on SrTiO3 (100) single crystal. By combining the experimental results with density functional theory plus U (DFT+U) calculations, we reveal that 2.1% in-plane tensile strain can stabilize the insulating state of LSCO with a surprisingly low concentration of oxygen vacancies, less than 0.5%. This study reveals that the MIT in LSCO is governed by the combination of oxygen vacancies and strain, offering the potential for additional tuning knob of the material's electronic properties.
Source: Applied Surface Science Advances
Authors: Yichen Wu, Victor Rosendal, Milica Vasiljevic, Imran Asghar, Vincenzo Esposito
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,970
OpenAlex ID: W4402943147