Effect of 130 keV pulsed electron irradiation on the efficiency of radiative transitions in Eu-doped glass-ceramics CaSiO3

Autor(es)

Gonzales-Lorenzo, Carlos D. ^{[1, 2]} ; Ananchenko, D. V. ^[3] ; Nikiforov, S. V. ^[3] ; Kiryakov, A. N. ^[3] ; Zatsepin, A. F. ^[3] ; Chubaci, Jose F. D. ^[2] ; Cano, N. F. ^[4] ; Ayala-Arenas, Jorge S. ^[1] ; Watanabe, Shigueo ^[2]

Afiliação do(s) autor(es)

^[1] Univ Nacl San Agustin UNSA, Fac Ciencias Nat & Formales, Escuela Profes Fis, Av Independencia S-N, Arequipa - Peru

^[2] Univ Sao Paulo Rua Matao, Inst Fis, Rua Matao, Travessa R, 187, BR-05508090 Sao Paulo, SP - Brazil

^[3] Ural Fed Univ, Ulitsa Mira 21, Ekaterinburg - Russia

^[4] Univ Fed Sao Paulo, Inst Mar, Rua Doutor Carvalho Mendonca 144, BR-11070100 Santos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Optical Materials; v. 119, SEP 2021.
• Citações Web of Science: 0

Resumo

Polycrystalline glass-ceramic CaSiO3 doped with Eu(3+ )ions was obtained by devitrification. The analysis of the photoluminescent characteristics of the obtained glass-ceramic is carried out. It was found that as a result of the devitrification of CaSiO3, two phases are formed, identified as pseudowollastonite (beta-CaSiO3) as the dominant phase together with a small percentage of tridymite (SiO2). The UV-Vis optical absorption of Eu3+-doped CaSiO3 was performed using a UV-Vis spectrophotometer. The main objective of this work was to study the effect of the pulsed corpuscular action of electrons accelerated in a field of 130 keV on energy transitions in the Eu3+ ion. It is found that, upon steady-state excitation of the photoluminescent signal in the PLE spectra of unirradiated samples at wavelengths below 300 nm, two broad excitation peaks are displayed, possibly associated with O Eu and O - Si CT transitions. Above 300 nm the characteristic excitation band from 7F0 ground state to H-5(j), D-5(4), (5)G(j), L-5(6), D-5(3), and D-5(2) states of the Eu3+ ions are shown. It was found that, as a result of exposure to an electron beam in the photoluminescence spectra of europium, a redistribution of the relative intensities of the 5D0 -{*} F-7(2) and D-5(0) -{*} F-7(1) transitions occurs. The calculation of the asymmetry ratio of these transitions showed values for an unirradiated sample R-21 = 2.06 and irradiated R-21 = 2.52, which indicates a decrease in the symmetry of the crystal field around Eu3+ ions after irradiation. Several reasons for the decrease in the relative intensity of the Eu3+ luminescence signal after electron irradiation, caused by the effect of electrization of the material, intrinsic defects of the matrix, and inhomogeneous phase composition, are discussed. (AU)

• Processo FAPESP: 14/03085-0 - Geocronologia do quaternário da costa Sudeste e Sul do Brasil
• Beneficiário: Shigueo Watanabe
• Modalidade de apoio: Auxílio à Pesquisa - Temático