Synthesis, Thermal Evolution, and Luminescence Properties of Yttrium Disilicate Host Matrix

Abstract

A new pressureless hydrothermal method for the preparation of yttrium disilicate is presented. The obtained amorphous precursor was calcined at different temperatures to form the Y-, R-, β-, and γ-phases of Y 2 Si 2 O 7 , which have been characterized by DTA, XRD, TEM, and 29 Si-MAS RMN and IR spectroscopy. It is shown that the proposed method allows the strictly controlled doping of yttrium disilicate using RE elements such as dysprosium (2.5 and 5 at. %). The luminescent properties, in terms of emission efficiency, of different polymorphs of Dy-doped Y 2 Si 2 O 7 have been investigated by fluorescence measurements at room temperature. The results indicate that the β-phase doped with 2.5 at.% has the maximum efficiency. It is important to note that the efficiency of this phase is approximately 40% of that measured for the commercial phosphor Eu-Y 2 O 3 .

Formation and characterization of Lu silicate nanoparticles in amorphous SiO2

“…7)). We could not find in the literature any IR spectra of B-type lanthanide silicates but in FT-IR spectrum of ␣-Y 2 Si 2 O 7 sample, which is supposed to have B-type structure, we observed a similar doublet of bands at 688 and 718 cm −1 (Table 3) in accordance with a spectrum shown in [24]. It is interesting that the difference in positions of the bands in the doublet in these silicates is very close and amounts to 31 ± 1 cm −1 .…”

Recent progress on synthesis, multi-scale structure, and properties of Y–Si–O oxides

“…[35][36][37][38] In this process, layered clay, saponite or smectits, is suspended in Y(NO 3 ) 3 solution, and then heated to 300uC or above in a hydrothermal tank for several days. The solid product collected by filtering was y-Y 2 Si 2 O 7 .…”

Synthesis of Y2Si2O7:Eu nanocrystal and its optical properties

“…The sharp peak of Si-O (1090 cm À1 ) splits into two absorption peaks at 800-1000 cm À1 (n as , Si-O-Si). When the samples were annealed at 900-1100 1C, the absorption peak at 540 cm À1 boosts up clearly due to the formation of Y 2 O 3 :Eu nanocrystalline and the increase of defects [20], which indicates the decomposition of Si-O-Y into Si-O-Si and Y-O. Based on the above analysis of FT-IR spectra and XRD patterns, the Y 2 Si 2 O 7 :Eu nanocrystalline was obtained by ultrasonic irradiation and annealing at 300-600 1C, and then decomposed into more stable SiO 2 and cubic Y 2 O 3 :Eu nanocrystalline by further heat treatment at 700-900 1C.…”