ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Cathodoluminescence and photoluminescence of BaTa₂O₆:Sm³⁺ phosphor depending on the sintering temperature

Mustafa İlhan and Lütfiye Feray Güleryüz

Department of Environmental Engineering, Faculty of Engineering, Marmara University, Kadıköy, İstanbul, Turkey

E-mail: mustafa.ilhan@marmara.edu.tr

Received: 14 April 2022  Accepted: 19 July 2022

Abstract:

The effect of sintering temperature on the structural and spectroscopic (CL, PL, decay) properties was investigated using 2.5 mol% Sm³⁺ doped BaTa₂O₆ samples, which were fabricated by solid state reaction at temperatures of 1150, 1250, 1350, 1425 °C. In XRD analysis of Sm³⁺ doped BaTa₂O₆ samples, orthorhombic phase appeared at temperatures of 1150 and 1250 °C, later the impurity phases disappeared at 1350 °C where orthorhombic polymorph completely transformed into a tetragonal tungsten bronze (TTB) structure. SEM analysis revealed the increase of grain size of Sm³⁺ doped BaTa₂O₆ with increasing sintering temperature. PL emissions were observed due to ⁴G_5/2 → ⁶H_J (J = 5/2, 7/2, 9/2, 11/2, 13/2) transitions of Sm³⁺ where the emissions increased with the effect of increasing temperature and reached maximum at 1425 °C. The increase of PL emissions can be attributed to the developing of the tetragonal phase crystallinity which led to the decrease of non-radiative centers. CL emission of the undoped sample sintered at 1425 °C was monitored by the broad blue peak at about 495 nm which is related with the intrinsic emission of BaTa₂O₆. CL emissions of the doped samples sintered between 1150 and 1425 °C showed the host emissions and characteristic emissions of Sm³⁺ corresponding to ⁴G_5/2 → ⁶H_5/2, ⁴G_5/2 → ⁶H_7/2, ⁴G_5/2 → ⁶H_9/2, ⁴G_5/2 → ⁶H_11/2 transitions. The Sm³⁺ concentration led to a decrease in the decay time and an increase in the energy transfer, while the sintering temperature effect showed a different process where the decay time and energy transfer slightly increased.

Keywords: Sm3+; TTB; Cathodoluminescence; Photoluminescence; Decay time

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02389-5

Chemical Papers 76 (11) 6963–6974 (2022)