The quantification of radiation damage in orthophosphates using confocal μ-luminescence spectroscopy of Nd³⁺

Author(s)

Christoph Lenz, Gordon J. Thorogood, Robert Aughterson, Mihail Ionescu, Daniel Gregg, Joel Davis, Greg R: Lumpkin

Abstract

In this study, we present a new concept based on the steady-state, laser-induced photoluminescence of Nd3+, which aims at a direct determination of the amorphous fraction f a in monazite- and xenotime-type orthophosphates on a micrometer scale. Polycrystalline, cold-pressed, sintered LaPO4, and YPO4 ceramics were exposed to quadruple Au-ion irradiation with ion energies 35 MeV (50% of the respective total fluence), 22 MeV (21%), 14 MeV (16%), and 7 MeV (13%). Total irradiation fluences were varied in the range 1.6 × 1013-6.5 × 1013 ions/cm2. Ion-irradiation resulted in amorphization and damage accumulation unto a depth of ~5 µm below the irradiated surfaces. The amorphous fraction created was quantified by means of surface-sensitive grazing-incidence X-ray diffraction and photoluminescence spectroscopy using state-of-the-art confocal spectrometers with spatial resolution in the µm range. Monazite-type LaPO4 was found to be more susceptible to ion-irradiation induced damage accumulation than xenotime-type YPO4. Transmission electron microscopy of lamella cut from irradiated surfaces with the focused-ion beam technique confirmed damage depth-profiles with those obtained from PL hyperspectral mapping. Potential analytical advantages that arise from an improved characterization and quantification of radiation damage (i.e., f a) on the µm-scale are discussed.

Organisation(s)

Department of Mineralogy and Crystallography

External organisation(s)

Australian Nuclear Science and Technology Organisation (ANSTO)

Journal

Frontiers in Chemistry

Volume

7

No. of pages

13

ISSN

2296-2646

DOI

https://doi.org/10.3389/fchem.2019.00013

Publication date

02-2019

Peer reviewed

Yes

Austrian Fields of Science 2012

104026 Spectroscopy, 105116 Mineralogy, 105113 Crystallography

Keywords

ASJC Scopus subject areas

General Chemistry

Portal url

https://ucrisportal.univie.ac.at/en/publications/a672eb6f-0786-4452-8a5a-12e19533f3d4