Structural and optical properties of Gd2SiO5 prepared from hydrothermally synthesized powder

Abstract

Cerium doped Gd2SiO5 (GSO) is an important scintillator material due to its high density and non-hygroscopic nature. GSO powder of uniform size and morphology synthesized by chemical method can be used as a source material to grow single crystals and to prepare transparent ceramics. In this work, rod-like Gd2SiO5 powder has been synthesized by hydrothermal reaction of precursors followed by a thermal treatment at 1400°C for 20h. Effect of various growth parameters on phase and morphology of the synthesized Gd2SiO5 has been investigated. The desired Gd2SiO5 phase is obtained for an appropriate concentration (∼0.5M) of the precipitating agent (NaOH) and molar ratio of precursors (Gd (NO3)3⋅6H2O: Si (OC2H5)4=2:1). A higher NaOH concentration and lower molar ratio of precursors (Gd:Si) result in the formation of additional phases. For the Gd:Si=1:1 ratio, a leaf-like structure of hexagonal Gd4.67 (SiO4)3O is obtained. Evolution of the desired phase GSO has been studied by the non-resonant Raman spectroscopy. Substitutional cerium doping up to 1at.% in the GSO initiates a preferred growth towards the [021] direction. The rod-shaped Ce doped GSO has an emission at 425nm for excitations at 280 and 345nm near room temperature.