Strong substrate influence on atomic structure and properties of epitaxial VO2 thin films

The metal–insulator transition (MIT) observed in vanadium dioxide has been a topic of great research interest for past decades, with the underlying physics yet not fully understood due to the complex electron interactions and structures involved. The ability to understand and tune the MIT behavior i...

Descripción completa

Detalles Bibliográficos
Autores: Atul, Atul, Ahmadi, Majid, Koutsogiannis, Panagiotis, Zhang, Heng, Kooi, Bart J.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/354790
Acceso en línea:http://hdl.handle.net/10261/354790
Access Level:acceso abierto
Palabra clave:Metal–insulator transition
Pulsed laser deposition
Scanning transmis-sion electron microscopy
VO2epitaxial thin films
Descripción
Sumario:The metal–insulator transition (MIT) observed in vanadium dioxide has been a topic of great research interest for past decades, with the underlying physics yet not fully understood due to the complex electron interactions and structures involved. The ability to understand and tune the MIT behavior is of vital importance from the perspective of both underlying fundamental science as well as potential applications. In this work, scanning transmission electron microscopy (STEM) is used to investigate cross-section lamella of the VO2 films deposited using pulsed laser deposition on three substrates: c-cut sapphire, TiO2(101) and TiO2(001). Advanced STEM imaging is performed in which also the oxygen atom columns are resolved. The overall film quality and structures on atomic and nanoscale are linked to the electrical transition characteristics. Relatively poor MIT characteristics are observed on c-sapphire due to the presence of very small domains with six orientation variants, and on TiO2 (001) due to the presence of cracks induced by stress relaxation. However, the MIT on TiO2 (101) behaves favorably, despite similar stress relaxation which, however, only leads to domain boundaries but no cracks.