Anomalous heating rate response of beta irradiated Sm3+ and Tb3+ doped BaAl2O4 phosphors


Kaynar Ü., Guvener E., AYVACIKLI M., DOĞAN T., Balci-Yegen S., Oglakci M., ...More

Journal of Alloys and Compounds, vol.764, pp.523-529, 2018 (SCI-Expanded, Scopus) identifier

  • Publication Type: Article / Article
  • Volume: 764
  • Publication Date: 2018
  • Doi Number: 10.1016/j.jallcom.2018.06.125
  • Journal Name: Journal of Alloys and Compounds
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.523-529
  • Keywords: Anomalous heating rate, BaAl2O4, Rare earth, Thermoluminescence
  • Manisa Celal Bayar University Affiliated: Yes

Abstract

The stuffed derivative of the tridymite structure, the oxide BaAl2O4 has been regarded as a long persistent phosphor. Thermoluminescence (TL) glow curve peaks of thin pellet samples of undoped and, Sm3+ and Tb3+ doped BaAl2O4 prepared by combustion method was reported. The structure of the compounds was monitored by X-ray diffraction and found a single-phase compound with a hexagonal structure. Performing a series of TL measurements for the temperature range from room temperature to 400 °C, the effect of beta radiation dose on TL response, various TL heating rate (HR) properties of undoped and Sm3+ and Tb3+ doped BaAl2O4 phosphors were investigated. Peak shape method was also utilized to assess the trap parameters. The activation energy of the main peak at 128 °C was found to be 0.97 eV. TL glow curves obtained from undoped and Tb3+ doped BaAl2O4 decrease with increasing HR value (varying from 0.5 to 15 °C s−1) in a way matching with thermal quenching effect. Contrary to expectations, anomalous HR dependence was observed on Sm3+ doped BaAl2O4 sample and a semi-localized transition model has been used in order to explain such behaviour.