40 research outputs found
"Etchability" of ion tracks in Si02/Si and Si3N4/Si thin layers
We have calculated radii and lifetime of the molten regions or the regions heated
to the melting point that are formed under irradiation of amorphous SiO2 and Si3N4 with
swift ions. A computer simulation was carried out on the base of thermal spike model. A
comparison of calculated track parameters with ion track etching data have been made
for these materials.
It is shown that an existence of molten region along swift ion trajectory may be a
criterion for a track “etchability” in the case of SiO2. In the same conditions of chemical
etching diameter of etched tracks in SiO2 is proportional to the radius and lifetime of the
molten region. This information is important for a correct choice of irradiation regime
aimed at preparation of nanoporous layers with high pore density ( 10 10 cm-2).
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2087
"Etchability" of ion tracks in Si02/Si and Si3N4/Si thin layers
We have calculated radii and lifetime of the molten regions or the regions heated
to the melting point that are formed under irradiation of amorphous SiO2 and Si3N4 with
swift ions. A computer simulation was carried out on the base of thermal spike model. A
comparison of calculated track parameters with ion track etching data have been made
for these materials.
It is shown that an existence of molten region along swift ion trajectory may be a
criterion for a track “etchability” in the case of SiO2. In the same conditions of chemical
etching diameter of etched tracks in SiO2 is proportional to the radius and lifetime of the
molten region. This information is important for a correct choice of irradiation regime
aimed at preparation of nanoporous layers with high pore density ( 10 10 cm-2).
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2087
Solid-state reactions between iridium thin films and silicon carbide in the 700 °C to 1000 °C temperature range
DATA AVAILABILITY :
Data will be made available on request.Please read abstract in the article.The National Research Foundation (NRF) of South Africa.https://www.elsevier.com/locate/mtcommhj2024PhysicsNon
Effect of Xe ion (167 MeV) irradiation on polycrystalline SiC implanted with Kr and Xe at room temperature
The effect of swift heavy ion (Xe 167 MeV) irradiation on polycrystalline SiC individually
implanted with 360 keV Kr and Xe ions at room temperature to fluences of 2×1016 cm-2 and
1×1016 cm-2 respectively, was investigated using transmission electron microscopy (TEM),
Raman spectroscopy and Rutherford backscattering spectrometry (RBS). Implanted
specimens were each irradiated with 167 MeV Xe+26 ions to a fluence of 8.3×1014 cm-2 at
room temperature. It was observed that implantation of 360 keV Kr and Xe ions individually
at room temperature amorphized the SiC from the surface up to a depth of 186 and 219 nm
respectively. Swift heavy ion (SHI) irradiation reduced the amorphous layer by about 27 nm
and 30 nm for the Kr and Xe samples respectively. Interestingly, the reduction in the
amorphous layer was accompanied by the appearance of randomly oriented nanocrystals in
the former amorphous layers after SHI irradiation in both samples. Previously, no similar
nanocrystals were observed after SHI irradiations at electron stopping powers of 33 keV/nm
and 20 keV/nm to fluences below 1014 cm-2. Therefore, our results suggest a fluence threshold for the formation of nanocrystals in the initial amorphous SiC after SHI irradiation.
Raman results also indicated some annealing of radiation damage after swift heavy ion
irradiation and the subsequent formation of small SiC crystals in the amorphous layers. No
diffusion of implanted Kr and Xe was observed after swift heavy ion irradiation.National Research Foundation (NRF)http://iopscience.iop.org0022-37272016-10-20hb201
Interface reactions between Pd thin films and SiC by thermal annealing and SHI irradiation
The solid-state reactions between Pd thin films and 6H-SiC substrates induced by thermal
annealing, room temperature swift heavy ion (SHI) irradiation and high temperature SHI
irradiation have been investigated by in situ and real-time Rutherford backscattering
spectrometry (RBS) and Grazing incidence X-ray diffraction (GIXRD). At room temperature,
no silicides were detected to have formed in the Pd/SiC samples. Two reaction growth zones
were observed in the samples annealed in situ and analysed by real time RBS. The initial
reaction growth region led to formation of Pd3Si or (Pd2Si+Pd4Si) as the initial phase(s) to
form at a temperature of about 450 °C. Thereafter, the reaction zone did not change until a
temperature of 640 °C was attained where Pd2Si was observed to form in the reaction zone.
Kinetic analysis of the initial reaction indicates very fast reaction rates of about 1.55×1015
at.cm-2/s and the Pd silicide formed grew linear with time. SHI irradiation of the Pd/SiC
samples was performed by 167 MeV Xe26+ ions at room temperature at high fluences of
1.07×1014 and 4×1014 ions/cm2 and at 400 °C at lower fluences of 5×1013 ions/cm2. The
Pd/SiC interface was analysed by RBS and no SHI induced diffusion was observed for room
temperature irradiations. The sample irradiated at 400 °C, SHI induced diffusion was
observed to occur accompanied with the formation of Pd4Si, Pd9Si2 and Pd5Si phases which
were identified by GIXRD analysis.http://www.elsevier.com/locate/nimb2017-03-31hb2016Physic
Surface and interface modification of Zr/SiC interface by swift heavy ion irradiation
In this study thin Zr films (135 nm) were deposited on 6H-SiC substrate at room temperature by sputter
deposition. The Zr/SiC couples were irradiated by 167 MeV Xe26+ ions at room temperature at fluences of
5.0 1012, 1.0 1013, 5.0 1013, 2.0 1014, 3.1 1014 and 6.3 1014 ions/cm2. The samples were analysed
before and after irradiation using Rutherford backscattering spectroscopy (RBS), atomic force
microscopy (AFM) and secondary electron microscopy (SEM). The surface morphology from SEM analysis
revealed a homogeneous Zr surface which did not vary with increasing fluences of irradiation. AFM analysis
revealed that the Rrms surface roughness did increase from the as-deposited value of 1.6 nm and then
decrease at higher SHI irradiation fluences to 1.4 nm. RBS results indicate that interface mixing between
Zr and SiC interface occurred and varied linearly with irradiation ion fluence. The value obtained for diffusivity
of Zr shows that the mixing was due to interdiffusion across the interface during a transient melt
phase according to the thermal spike model.http://www.elsevier.com/locate/nimb2016-07-01hb201
Effect of thermal annealing on SHI irradiated indium implanted glassy carbon
Please read abstract in the article.The National Research Foundation (NRF) of South Africa and the University of Pretoria.http://www.elsevier.com/locate/nimb2022-06-22hj2022Materials Science and Metallurgical EngineeringPhysic
Effects of Ag and Sr dual ions implanted into SiC
Please read abstract in the article.National Research Foundation of South Africa, Knowledge Interchange and Collaboration Programme (KIC).http://www.elsevier.com/locate/nimbhj2021Physic