Anomalous change in dielectric constant of CaCu3Ti4O12 under violet-to-ultraviolet irradiation
Abstract
The influence of light illumination on the dielectric constant of CaCu3Ti4O12 (CCTO) polycrystals is studied in this work. When exposed to 405-nm laser light, a reversible enhancement in the room temperature capacitance as high as 22% was observed, suggesting application of light-sensitive capacitance devices. To uncover the microscopic mechanisms mediating this change, we performed electronic structure measurements, using photoemission spectroscopy, and measured the electrical conductivity of the CCTO samples under different conditions of light exposure and oxygen partial pressure. Together, these results suggest that the large capacitance enhancement is driven by oxygen vacancies induced by the irradiation.
Citation
Masingboon , C , Eknapakul , T , Suwanwong , S , Buaphet , P , Nakajima , H , Mo , S -K , Thongbai , P , King , P D C , Maensiri , S & Meevasana , W 2013 , ' Anomalous change in dielectric constant of CaCu3Ti4O12 under violet-to-ultraviolet irradiation ' , Applied Physics Letters , vol. 102 , no. 20 , 202903 . https://doi.org/10.1063/1.4807741
Publication
Applied Physics Letters
Status
Peer reviewed
ISSN
0003-6951Type
Journal article
Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.