Drastic reduction of the slow scintillation component in highly luminescent Ce3+ and Mg2+ doped Lu2.5Gd0.5Ga2Al3O12 garnet powders

TL;DR

This study presents a photochemical method to synthesize highly luminescent Ce3+ and Mg2+ doped Lu2.5Gd0.5Ga2Al3O12 garnet powders, achieving doping levels difficult with traditional melt growth, and analyzes their structural and luminescent properties.

Contribution

It introduces a novel photochemical synthesis approach for garnet powders with controlled doping, enabling new doping levels and improved luminescent properties.

Findings

Doped garnet powders are phase-pure and chemically pure.

Luminescence spectra show characteristic Ce3+ and Gd3+ emissions.

Doping concentrations affect RL intensity, light yields, and decay times.

Abstract

This paper deals with the photochemical preparation of nanomaterials with garnet structure. Ce3+ and Mg2+ doped Lu2.5Gd0.5Ga2Al3O12 powders were prepared by using UV irradiation of aqueous solutions with low-pressure mercury lamps and subsequent calcination of the solid products. The synthesis was optimized and gives access to a range of doping which is very hard to achieve with single crystal growth from melt. The effect of Ce and Mg concentration on the structural and luminescence properties was studied. Garnets were analyzed using X-ray fluorescence (XRF) and X-ray powder diffraction (XRPD) and their luminescence properties under optical and X-ray photon excitations were investigated. XRF and XRD show that the samples are sufficiently chemically pure and phase-pure and their elemental composition corresponds with expectations. Laser-induced breakdown spectroscopy confirmed that Mg concentrations in Mg-codoped samples are slightly lower than the nominal. Luminescence spectra show typical emission maxima of 5d-4f Ce3+ transition and 4f-4f Gd3+ transition. The effects of the concentration of Ce3+ and Mg2+ on the RL intensity, light yields and decays were observed.