In-situ RBS studies of strontium implanted glassy carbon

Abstract

Highlights• Glassy carbon samples were implanted with 200 keV Sr ions at room temperature to a fluence of 1 × 10 16 Sr + /cm 2 . The implanted samples were annealed in vacuum at temperature ranging from 23 °C-650 °C and in-situ real-time RBS analysis was carried out during the annealing process in order to investigate the diffusion behaviour of the implanted strontium.• The vacancy distribution profile derived from SRIM simulation shows that the radiation damage introduced by ion bombardment is concentrated towards the surface region of the glassy carbon substrate.• During low temperature annealing, the Sr atoms moved deeper into the bulk of the glassy carbon substrate due to the presence of vacancy and interstitial defects in the surface region of the glassy carbon. Migration of the implanted Sr towards the surface of the glassy carbon was observed at temperatures ranging from 560 °C-650 °C.• Migration of the implanted Sr towards the surface of the glassy carbon was observed at temperatures ranging from 560 °C-650 °C. The migration towards the surface was accompanied with segregation of Sr towards the surface. The segregated strontium was retained on the glassy carbon substrate and no loss of strontium was recorded.• The diffusion of Sr was limited to the damaged region of the glassy carbon and no diffusion into the pristine glassy carbon was observed. The results of the study show that glassy carbon is an excellent containment material for radioactive strontium. ABSTRACTThe diffusion behaviour of strontium in glassy carbon was investigated using in-situ real time

Diffusion of strontium implanted in glassy carbon

“…For the isochronal annealing measurements, the samples were placed in a turbo-pumped vacuum tube furnace with a base pressure of about 10 −7 mbar and the temperature was measured by a thermocouple close to the sample; see [21] for more details. The samples were sequentially annealed for 1 h each from 200 to 900°C in steps of 100°C.…”

“…A key property for a nuclear waste storage material is low diffusivity for the radioactive materials. Although there had been a few reports of diffusion of fission product elements in glassy carbon [17][18][19][21][22][23][24][25][26], this is the prime reason for this study, i.e. to determine the diffusivity of the radiological important fission product, strontium, in glassy carbon.…”

“…Conventional sequential isochronal vacuum annealing was done with the Sr depth profiles determined by RBS after each annealing temperature. In the other method, the vacuum annealing temperature was increased linearly while doing simultaneously non-destructive RBS depth profiling to determine the diffusion of the implanted strontium in glassy carbon at small temperature intervals of 4 K. These RBS profiles were previously reported [21] before the mathematical model given in appendix A was developed. That paper only gave a qualitative analysis of the results and without the analytical equations to determine diffusion coefficients.…”

In situ модификация и анализ состава и кристаллической структуры кремниевой мишени с помощью ионно-пучковых методик

“…Материал BFO является перспективным для производства устройств спинтроники, сенсоров и носителей данных. В работе [13] методом резерфордовского обратного рассеяния была изучена диффузия стронция в стекловидном углероде (glassy carbon) при разработке емкости для хранения радиоактивных отходов.…”

Structural modification of indium implanted glassy carbon by thermal annealing and SHI irradiation

“…For GC to be a good candidate for containment, it must be a good diffusion barrier for fission products and its near-surface region structure must remain unchanged so that it retains its properties after In implantation, annealing and even after swift heavy ion (SHI) irradiation. Previous work on ion species implanted in GC include Be [18], Cs [19], Sr [20], Co [4] K [21], Na [15], Ti [22], N [23], W [17], Cd [24] but after extensive literature research no study of In implanted in GC has been carried out and no study on SHI irradiation of implanted GC has been previously conducted. The diffusion coefficient calculated in this study after isochronal annealing has been compared to that of beryllium implanted into GC calculated by Koskelo et al [18].…”