Inferring relative dose-dependent color center populations in proton irradiated thoria single crystals using optical spectroscopy

Abstract

We have utilized photoluminescence spectroscopy and optical ellipsometry to characterize the dose-dependence of the photoluminescence emission intensity and changes in optical absorption of thoria single crystals subject to irradiation with...

A combined theoretical-experimental investigation of thermal transport in low-dose irradiated thorium dioxide

“…The optical absorption spectra also did not show any distinct bands in the visible spectrum. The PL spectra on the irradiated ThO2 crystals, however, revealed two distinct peaksone at ~1.67 eV, and another sharp peak at ~1.94 eV, in agreement with PL peaks reported in ThO2 crystals irradiated with protons to higher doses [37]. While the intensity of the 1.67…”

“…The plateau damage dose for the two room temperature irradiated samples was 0.004 dpa and 0.01 dpa, while the corresponding dose for the three samples irradiated at 600°C varied between 0.01 dpa and 0.1 dpa. previously for ThO2 single crystals irradiated to higher dose levels [37]. A 532 nm (2.33 eV) continuous wave (CW) laser was used for photoexcitation in the PL measurements.…”

“…A 532 nm (2.33 eV) continuous wave (CW) laser was used for photoexcitation in the PL measurements. PL peaks and the optical absorption bands observed in the spectra measured on the irradiated ThO2 crystals were attributed to creation of new electronic states emerging from charged and neutral oxygen vacancy defects created by atomic displacement damage [31,37]. Therefore, these optical spectroscopy techniques provide an indirect means to characterizing the population of oxygen anion vacancy defects at the earliest stages of damage accumulation that cannot be readily imaged using electron microscopy.…”

Towards quantitative inference of nanoscale defects in irradiated metals and alloys

“…In non-metals, these defects can often be characterized through optical spectroscopic techniques such as Raman spectroscopy [19], optical ellipsometry [20], photoluminescence [20], and others. In Raman-active materials, the vibrational modes of different bonds give unique signatures that can be probed optically and provide insight into defects as small as isolated vacancies and interstitials.…”

Towards Quantitative Inference of Nanoscale Defects in Irradiated Metals and Alloys

“…In non-metals, these defects can often be characterized through optical spectroscopic techniques such as Raman spectroscopy (Shelyug et al, 2018), optical ellipsometry (Khanolkar et al, 2022), photoluminescence (Khanolkar et al, 2022), and others. In Raman-active materials, the vibrational modes of different bonds give unique signatures that can be probed optically and provide insight into defects as small as isolated vacancies and interstitials.…”