Structural and spectroscopic properties of phosphate-tungsten glasses doped with Nd3+ and Tb3+

Author(s)

Guidini, Priscila ^[1] ; Galleani, Gustavo ^[1] ; Faria, Walter ^[1] ; Silva, Igor D. A. ^[1] ; Eckert, Hellmut ^{[1, 2]} ; de Camargo, Andrea S. S. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Fis Sao Carlos, CP 369, BR-13560970 Sao Carlos, SP - Brazil

^[2] Westfalische Wilhelms Univ Munster, Inst Phys Chem, D-48149 Munster - Germany

• Document type: Journal article
• Source: Journal of Non-Crystalline Solids; v. 529, FEB 1 2020.
• Web of Science Citations: 0

Abstract

Glasses of composition 90NaPO(3)-10WO(3)-xNd(2)O(3), (0 <= x <= 1.7 mol%) and 90NaPO(3)-10WO(3)-yTbF(3), (0 <= y <= 5.0 mol%) have been prepared and characterized. P-31 and Na-23 magic-angle spinning (MAS) NMR and Na-23[P-31] rotational echo double resonance results are consistent with previously published data, indicating the presence of Q((2)) and Q(1 W)((1)) units. In addition, linear dependences of P-31 MAS-NMR linewidths and spin-lattice relaxation rates and the electron spin-spin relaxation behavior (in the case of Nd2O3 doping) are consistent with a random dopant distribution, For Nd2O3- doped glass samples, absorption spectra in the visible and infrared regions were collected and analysed, and photoluminescence excitation and emission spectra were obtained under 575 nm excitation. Using the Judd-Ofelt formalism, the Omega(2), Omega(4) and Omega(6) parameters were determined and by using them, the radiative lifetime (tau(r)) were calculated for the F-4(3/2) excited state. The fluorescence quantum efficiency value for this level (QE = tau(f)/tau(r)) of 13% was determined for glass with x = 1.0. The photophysical properties of Tb- doped glasses were also studied and upon UV excitation (372 nm) the glasses show emissions in the green (540 nm, D-5(4) -> F-7(5) transition) and blue (434 nm, D-5(3) -> F-7(4)). The relative luminescence intensity ratio D-5(3) -> F-7(5)/D-5(4) -> F-7(5) is higher for lower Tb3+ content (0.5 Tb glass sample), because for higher Tb3+ contents, a cross-relaxation energy transfer process takes place favoring the green emission. (AU)

• FAPESP's process: 18/03931-9 - Preparation of fluoride-phosphate glass and glass-ceramics doped with rare-earth ions for potential use as radiation detectors
• Grantee: Gustavo Galleani
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass
• Grantee: Edgar Dutra Zanotto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC