Anomalous luminescent properties in ZnO and SrAl2O4 composites

V. P. Singh, P. Mohanty, S. P. Lochab, Chandana Rath

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

We have reported previously in a ZnO-SrAl2O4 composite synthesized through a solution combustion route that by dispersing 20 wt% of ZnO in the SrAl2O4 matrix and calcining at 700 °C, a stable hexagonal phase of SrAl2O4 at RT is established which is generally a high temperature phase of SrAl 2O4 reported in the literature [Singh et al. 2014 Dalton Transactions]. By increasing the calcination temperature of the composite to 1200 °C, the hexagonal phase transforms into a stable, monoclinic phase of SrAl2O4. In addition, we have observed anomalous luminescent properties in these composites. In photoluminescence spectra, we observe near band edge emission and defect band emission (DBE) corresponding to ZnO without any signature of emission corresponding to SrAl2O 4 in both the composites. The DBE peak is found to be stronger in the monoclinic phase than that observed in the hexagonal phase of SrAl 2O4, indicating more defects in the former composite. Combining the excitation and emission properties, we propose a tentative model to illustrate the mechanism of excitation and emission processes involved in the composites. Thermoluminescence studies show a common glow peak at ∼323 °C in both composites and an additional glow peak at ∼158 °C in the composite with the monoclinic phase. An additional glow peak further confirms more defects in the monoclinic phase than in the hexagonal phase corroborating with PL and XRD results. With increasing γ-irradiation dose, the additional glow peak shows a linear dosimetric response. The composite with the monoclinic phase seems to be suitable for dosimetric application which will be confirmed after doing more measurements in future.

Original languageEnglish
Pages (from-to)36765-36770
Number of pages6
JournalRSC Advances
Volume4
Issue number69
DOIs
Publication statusPublished - 2014
Externally publishedYes

ASJC Scopus subject areas

  • General Chemistry
  • General Chemical Engineering

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