On the athermal origin of flash sintering: Separating field-induced effects from Joule heating using a current ramp approach

Joule heating is generally acknowledged as the main driving force behind Flash Sintering. However, this view is challenged by the presence of athermal phenomena and the similarities between the flash process and dielectric breakdown. This work offers new insights into flash as an electrical runaway....

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Detalles Bibliográficos
Autores: Molina Molina, Sandra, Perejón Pazo, Antonio, Pérez Maqueda, Luis A., Sánchez Jiménez, Pedro Enrique
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/159351
Acceso en línea:https://hdl.handle.net/11441/159351
https://doi.org/10.1016/j.scriptamat.2024.116086
Access Level:acceso abierto
Palabra clave:Flash sintering
Electric field
Joule heating
Current ramp
Zinc oxide
Descripción
Sumario:Joule heating is generally acknowledged as the main driving force behind Flash Sintering. However, this view is challenged by the presence of athermal phenomena and the similarities between the flash process and dielectric breakdown. This work offers new insights into flash as an electrical runaway. Using current ramps to perform flash experiments on zinc oxide, two distinct stages within the process were revealed by electrical, thermal and microstructural measurements: a field-dominated regime where the flash event is triggered and a subsequent current-dominated regime associated with power dissipation. The contribution of each regime to the whole flash process was found to be determined by the initial resistivity of the sample. Furthermore, impedance spectroscopy data confirmed field-induced enhancement of conductivity at the flash-onset without significant Joule heating.