Modification of the spectroscopic properties of Tb2O3 phosphor under the high-pressure phase transitions sequence

JOURNAL OF ALLOYS AND COMPOUNDS

卷:859

Article

Candela, M. T.^1,3  Aguado, F.^2,3  Gonzalez-Lavin, J.¹  Gonzalez, J. A.^2,3  Valiente, R.^1,3 

[1] Univ Cantabria, Appl Phys Dept, Avda Los Castros 48, Santander 39005, Spain

[2] Univ Cantabria, CITIMAC Dept, Avda Los Castros 48, Santander 39005, Spain

[3] IDIVAL, Nanomed Grp, Avda Cardenal Herrera Oria, Santander 39011, Spain

关键词: Phosphors;    High-pressure;    Phase transitions;    Luminescence;    Inelastic light scattering;   

DOI  :  10.1016/j.jallcom.2020.157899

来源: Elsevier

【 摘 要 】

The high-pressure behavior of cubic Tb2O3 phase (C-type) has been investigated by in situ photoluminescence and Raman spectroscopy up to 18 GPa and 22 GPa, respectively. The luminescence spectrum of Tb2O3 at ambient conditions shows its characteristic sharp-line emission bands with the most intense one corresponding to the D-5(4) -F- 7(5) transition, responsible for the green emission. Excitation and emission spectra measured at low temperature and at different emission and excitation wavelengths suggest that photoluminescence is governed by the Tb3+ in the non-centrosymmetric site (C-2). A phase transition between 7.2 and 8.6 GPa is observed by Raman and photoluminescence experiments and is associated with a cubic-to-monoclinic (B-type) structural transformation. From 14 GPa the predominant modes in the Raman spectrum correspond to those from the trigonal phase (A-type), indicating that the pressure-induced structural phase transition sequence of Tb2O3 is C -> B -> A. Upon pressure release, the starting cubic phase is not recovered, but the monoclinic one. (C) 2020 Elsevier B.V. All rights reserved.

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