Comparative study of radiation-induced damage in magnesium aluminate spinel by means of IL, CL and RBS/C techniques

Abstract

International audienceA comparative study of damage accumulation in magnesium aluminate spinel (MgAl2O4) has been conducted using ionoluminescence (IL), cathodoluminescence (CL) and Rutherford Backscattering Spectrometry/channeling (RBS/C) techniques. MgAl2O4 single crystal and polycrystalline samples were irradiated with 320 keV Ar+ ions at fluencies ranging from 1 × 1012 to 2 × 1016 cm−2 in order to create various levels of radiation damage. RBS/C measurements provided quantitative data about damage concentration in the samples. These values were then compared to the luminescence measurements. The results obtained by IL and RBS/C methods demonstrate a two-step character of damage buildup process. The CL data analysis points to the three-step damage accumulation mechanism involving the first defect transformation at fluencies of about 1013 cm−2 and second at about 1015 cm−2. The rate of changes resulting from the formation of nonluminescent recombination centers is clearly nonlinear and cannot be described in terms of continuous accumulation of point defects. Both, IL and CL techniques, appear as new, complementary tools bringing new possibilities in the damage accumulation studies in single- and polycrystalline materials

Damage accumulation studies in ion-irradiated oxides: Current status and new perspectives

“…Several advanced techniques were tested for this purpose. Among them luminescence and Raman are certainly the most promising ones [22,23].…”

“…A significant advantage of IL is the possibility to adjust the range of ions used for excitation to the thickness of the damaged layer, hence to eliminate the signal coming from deeper undamaged parts of the material. An example of such experiments performed on mono-and polycrystalline MgAl 2 O 4 samples irradiated with 320 keV Ar ions is presented in [22]. In this work a H 2 ion beam with an energy of 86 keV was used to excite the luminescence.…”

“…The use of luminescence to magnesium aluminate spinel clearly indicated the existence of new defect transformation appearing at very low (∼2 × 10 13 cm −2 ) irradiation fluence which cannot be identified by RBS/C. Raman spectroscopy may also be used for the study of damage production in ion-irradiated mono-and polycrystalline materials [22,24]. Serious advantages of this technique are: (i) its speed of execution, (ii) the possibility to record data in situ during irradiation, and (iii) the capacity to extract depth distribution profiles.…”

Observation of Stabilized Tetragonal Latent Tracks Induced by Single SHI Impacts in Monoclinic Natural Zirconia at Room Temperature

“…This "apparent" fluence threshold for the m → t transformation is probably due to the detection limit (which is about 1%) of the applied analytical techniques such as XRD and the Raman spectroscopy. Other techniques used to calculate the ion damage to zirconia were ionoluminescence (IL), cathodoluminescence (CL), and Rutherford backscattering spectrometry/channeling (RBS/C) techniques which were used in combination with molecular dynamics (MD) simulations and phenomenological modelling [8]. However, all the above mentioned techniques were applied to materials irradiated to high fluences.…”