The Quantification of Radiation Damage in Orthophosphates Using Confocal μ-Luminescence Spectroscopy of Nd3+

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.

Partial amorphization of experimentally shocked plagioclase: A spectroscopic study

“…), and thus are similar to Raman spectroscopy, a practical probe for the characterization of local structural disorder (Lenz et al. ). In analogy to Raman spectra, Nd 3+ luminescence bands likewise broaden with increasing degree of amorphization (see again Fig.…”

An in-situ electron microscopy study of dual ion-beam irradiated xenotime-type ErPO4

“…[27] However, based on photoluminescence spectra and TEM results, the damage accumulation in xenotime (YPO4) samples were observed to be heterogenous in the irradiated surface layer and that the amorphous fraction was observed to decrease unto a depth of 5 µm. [27] The heterogenous damage layer observed in the YPO4 ceramics were proposed to be a result of the epitaxial annealing occurring at the crystalline-amorphous interface. [27] To the best of our knowledge, the impact of light-ions such as He + on the structure of pristine/amorphous xenotime has not been studied.…”

“…[26] Lenz et al in a recent study implanted xenotime-type (YPO4) ceramics sequentially with Auions of different energies (35,22,14,7 MeV) and fluences (1.6 × 10 13 -6.5 × 10 13 ions/cm 2 ) and determined the amount of amorphous fraction using photoluminescence spectroscopy. [27] Quadruple high energy Auions were chosen in that study in order to create an homogenous thick damage layer of ~5µm. [27] However, based on photoluminescence spectra and TEM results, the damage accumulation in xenotime (YPO4) samples were observed to be heterogenous in the irradiated surface layer and that the amorphous fraction was observed to decrease unto a depth of 5 µm.…”

“…[27] Quadruple high energy Auions were chosen in that study in order to create an homogenous thick damage layer of ~5µm. [27] However, based on photoluminescence spectra and TEM results, the damage accumulation in xenotime (YPO4) samples were observed to be heterogenous in the irradiated surface layer and that the amorphous fraction was observed to decrease unto a depth of 5 µm. [27] The heterogenous damage layer observed in the YPO4 ceramics were proposed to be a result of the epitaxial annealing occurring at the crystalline-amorphous interface.…”

“…[27] The heterogenous damage layer observed in the YPO4 ceramics were proposed to be a result of the epitaxial annealing occurring at the crystalline-amorphous interface. [27] To the best of our knowledge, the impact of light-ions such as He + on the structure of pristine/amorphous xenotime has not been studied. In this regard, the present study aims to address the question whether α-particles could induce a healing effect on the structure of amorphized…”