Evaluation of argon ion impact parameters in aluminium oxide by means of SRIM program and investigation of the effect of argon ion implantation on the thermoluminescence properties aluminium oxide

Abstract

The thermoluminescence properties of aluminium oxide (alumina) implanted with 80 keV argon ions at fluences in the range of $1\times {10}^{14}\text{--}1\times {10}^{16}\text{A}{\text{r}}^{+}/\text{c}{\text{m}}^2$ were investigated. The unimplanted and implanted samples were irradiated at a dose of 40 Gy and heated at a rate of 1°C/s. The glow curve of unimplanted and implanted samples shows 5 distinct peaks; the main dosimetric peak and four other peaks of lower intensity. In this study, our analysis has focussed on the main dosimetric peak located at 180°C, 191°C, 177°C, 208°C, 219°C and 207°C for the unimplanted sample and implanted samples respectively. It was observed that the TL intensity decreases with fluence of implantation. This suggests that ion implantation decreases the concentration of electron traps responsible for thermoluminescence. It can also be suggested that competition effects involving radiative pathways and non-radiative competitor traps may lead to a low thermoluminescence signal in the implanted samples in comparison to the unimplanted thermoluminescence signal. These competitive processes will tend to favour first-order kinetics, and consequently lead to a strong stability of the glow curve shapes. The creation of defect clusters as well as extended defects could also be responsible for the reduction in TL signal. The stopping and range of atoms in matter (SRIM) was used to evaluate the ion impact parameters including ion range, vacancy distribution and energy loss in Al₂O₃. Subsequent to ion implantation, it was found that the number of oxygen vacancies which are related to electron traps are higher than the number of aluminium vacancies. Kinetic analysis was carried out by means of the initial rise, Chen’s peak shape, various heating rate, the whole glow curve, glow curve fitting and isothermal decay methods. The activation energy was found to be around $0.8\text{eV}$ and the frequency factor to be of the order ${10}^8{\text{s}}^{-1}$ regardless of the implantation fluence. The dosimetric features of samples were also investigated at doses in the range of 40–200 Gy. Samples generally showed a superlinear response at doses less than 140 Gy and sublinear response at doses higher than 160 Gy.

KEYWORDS:

• Aluminium oxide
• argon
• thermoluminescence
• ion implantation
• kinetic analysis
• oxygen vacancies

Acknowledgements

We are grateful to Rhodes University and the National Research Foundation (through iThemba LABS Cape Town) for financial support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

S. Nsengiyumva

Prof S. Nsengiyumva is an associate professor at Rhodes University, Department of Physics and Electronics. He completed his phD at the University of Cape Town in 2008. Before joining Rhodes University as a lecturer in 2010, he was a postdoctoral fellow at the University of Cape Town. He was promoted to senior lecturer position and associate professor in 2015 and 2022 respectively. Prof Nsengiyumva has published various articles in peer-reviewed journals. He has been a reviewer of various journals including journal of hydrogen energy, journal of crystals, journal of radiation effects and defects in solids and journal of materials science. Prof Nsengiyumva is a C2 rated researcher by the national research foundation of South Africa. He is the main author of this article.

B. Khabo

Mr B. Khabo completed his bachelor degree at the University of Cape Town in 2018 before enrolling for a masters degree at the University of Rhodes. Mr Khabo undertook his masters degree research under the supervision of Prof Nsengiyumva. Mr Khabo is a co-author of this article.

N. Mongwaketsi

Dr N. Mangwaketsi is a senior research scientist at iThemba LABS, a national research facility in Cape Town, South Africa. She completed her PhD at the University of Stellenbosch. At iThemba LABS, she is involved in research and traing related to ion beam analysis in materials.She has published in various peer-reviewed journals such as nanomaterials and nanotechnology, nuclear instruments methods B, surface and interface analysis. Dr Mongwaketsi is one of my collaborators at iThemba LABS and a co-author of this article.

L. Pichon

Prof L. Pichon is one of the co-authors of this article. He is based at the University of Poitiers, France. He has been our collaborator since 2010 and contributed to various articles we have published in Radiation Effects and Defects in Solids Journal. The ion implantation we have carried out on our samples has been performed at the facility housed in the University of Poitiers.