Photoelectric Current and Dielectric Properties of Barium-Strontium Niobate Ceramics under UV and Visible Irradiation

• Published in: Ferroelectrics Vol. 485; no. 1; pp. 179 - 185
• Main Authors: Bormanis, K., Burkhanov, A. I., Nhan, Luu Thi, Mednikov, S. V., Antonova, M.
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 26-08-2015; Taylor & Francis Ltd
• Subjects: Ceramics; dielectric permittivity; Dielectric properties; Electric currents; Ferroelectric ceramics; Ferroelectrics; Frequencies; Phase transitions; photocurrent; visible and UV irradiation
• ISSN: 0015-0193; 1563-5112
• DOI: 10.1080/00150193.2015.1061880

A study of photocurrent kinetics and dielectric response to infra-low frequencies in the range of the broad phase transition in the Ba
0.25
Sr
0.75
Nb
2
O
6
(BSN-75) relaxor ceramics under visible and ultraviolet radiation is reported. Anomalies are revealed in the dependence on field intensity of dielectric permittivity and dielectric loss determined from measurements of polarisation loops before and after illumination. The effects of pyro-electric space charge, polarisation and photovoltaic contributions on behaviour of the measured photocurrent are discussed. Results of the kinetics of photocurrent and dielectric response to infra-low frequency studied at different temperatures are discussed as the effects of non-equilibrium carriers on relaxation of polarisation. Kinetics of the photocurrent in ceramics and single crystals is found to be similar.