Self-Pixelation Through Fracture in VO2 Thin Films

Vanadium dioxide (VO2) is an archetypal Mott material with a metal–insulator transition (MIT) at near room temperature. In thin films, this transition is affected by substrate-induced strain but as film thickness increases, the strain is gradually relaxed and the bulk properties are recovered. Epita...

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Detalles Bibliográficos
Autores: Rodríguez, Laura, Del Corro, Elena, Conroy, Michele, Moore, Kalani, Sandiumenge, Felip, Domingo, Neus, Santiso, José, Catalán, Gustau
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2020
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/231250
Acceso en línea:http://hdl.handle.net/10261/231250
Access Level:acceso abierto
Palabra clave:Metal−insulator transition
Thin films
Vanadium dioxide
Cracks
Pixelation
Scanning Kelvin probe microscopy
Descripción
Sumario:Vanadium dioxide (VO2) is an archetypal Mott material with a metal–insulator transition (MIT) at near room temperature. In thin films, this transition is affected by substrate-induced strain but as film thickness increases, the strain is gradually relaxed and the bulk properties are recovered. Epitaxial films of VO2 on (001)-oriented rutile titanium dioxide (TiO2) relax substrate strain by forming a network of fracture lines that crisscross the film along well-defined crystallographic directions. This work shows that the electronic properties associated with these lines result in a pattern that resembles a “street map” of fully strained metallic VO2 blocks separated by insulating VO2 stripes. Each block of VO2 is thus electronically self-insulated from its neighbors, and its MIT can be locally induced optically with a laser, or electronically via the tip of a scanning probe microscope so that the films behave functionally as self-patterned pixel arrays.