Search results for "Annealing"
showing 10 items of 434 documents
LiF crystals irradiated with 150MeV Kr ions: Peculiarities of color center creation and thermal annealing
2013
Abstract Color centers in LiF crystals are studied under irradiation at room temperature with 150 MeV Kr ions in the fluence (Φ) range of 1010–1014 ions/cm2 with a beam current density of 10, 50, and 100 nA/cm2, corresponding to flux of 4.46 × 109, 2.23 × 1010 and 4.46 × 1010 ions/(cm2 × s), respectively. At Φ ⩾ 3 × 1012 ions/cm2 besides F and Fn centers also charged F 3 + centers are created. Thermal annealing of irradiated LiF crystals with Φ ⩾ 1013 ions/cm2 at 400 K leads to a decrease of F centers (due to annihilation with H centers) and an enhancement of complex Fn color centers (neutral and charged) due to interaction with thermally activated anion vacancies. Annealing LiF crystals at…
Color centers and nanodefects in LiF crystals irradiated with 150MeV Kr ions
2012
Abstract The modifications of structure, optical and nano-mechanical properties of LiF crystals after irradiation with 150-MeV Kr +14 ions at a fluence of 6 × 10 12 ions cm −2 have been studied using optical absorption spectroscopy, scanning electron and atomic force microscopy, and nanoindentation. Optical spectroscopy shows the saturation of F centers and a comparatively high number of F n centers. AFM and SEM imaging reveals a nanostructured region with columnar nanocrystallites (size 30–90 nm). Nanostructuring occurs in depths up to 10 μm, where the ion energy loss surpasses a critical threshold of about 10 keV/nm. At a lower energy loss a zone enriched with dislocations is observed. S…
Thermal annealing and transformation of dimer F centers in neutron-irradiated Al2O3 single crystals
2020
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2020 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. In addition, the research leading to these results has received funding from the Estonian Research Council grant (PUT PRG619).
Ion-sputtering deposition of Ca–P–O films for microscopic imaging of osteoblast cells
2007
Abstract An ion-beam sputtering technique was used to produce Ca–P–O films on borosilicate glass at room temperature from hydroxyapatite targets using nitrogen, argon and krypton beams at different acceleration voltages. The sputtering target was pressed from high purity hydroxyapatite powder or mixture of high purity hydroxyapatite powder and red phosphorus in order to optimise the film composition. The film composition, determined using time-of-flight elastic recoil detection analysis (TOF–ERDA), was found to be strongly dependent on the ion energy used for deposition. By extra doping of the target with P the correct Ca/P atomic ratio in the deposited films was reached. The films deposite…
Formation of cobalt silicide films by ion beam deposition
2006
Abstract Thin films of cobalt silicide are widely used as metallization in very large-scale integrated electronic circuits. In this study, Co ions were deposited on Si(1 1 1) wafers by a high beam current filter metal vacuum arc deposition (FMEVAD) system. Surface silicide films were formed after annealing from 500 to 700 °C for 30 min. The results show that a thin CoSi2 surface layer with both a smooth surface topography and sharp interface can be achieved by annealing at 700 °C. The CoSi phase and O contamination were observed in the samples that were annealed at lower temperatures.
Annealing reactions in lead implanted copper
2002
Abstract The terminal solubility of Pb in Cu is extremely low and does not exceed 0.09 at.% at 875 K. Ion implantation of lead ions at 100 keV into Cu single crystals produces metastable solutions. Annealing of the samples causes redistribution of the implanted atoms to equilibrium or near-equilibrium aggregate states which may be reflected in a change in the type of impurity lattice location in the host matrix. We have studied the effect of annealing on single crystalline Cu implanted at temperatures around 375 K with Pb to a concentration of a 1–2 at.%. Rutherford backscattering/channeling analysis and transmission electron microscopy of the as-implanted samples have shown that the implan…
Formation of cobalt silicide from filter metal vacuum arc deposited films
2006
The thermal reaction of Co film deposited on Si(111) surfaces by a high current filter metal vacuum arc (FMEVAD) system has been studied. After deposition the films were annealed over the 400-900 degrees C temperature range for 30 min. Rutherford backscattering spectrometry (RBS) was used to characterize the elemental depth distributions in the films subjected to different annealing temperatures. Ordered chemical phases were determined by glancing-incidence X-ray diffraction (GIXRD) and the morphology was determined by cross section transmission electron microscopy (TEM). The results show that the phases formed are Co2Si at 400 degrees C, CoSi + Coo at 500 degrees C, CoSi + CoSi2 at 600 deg…
Kinetics of the electronic center annealing in Al2O3 crystals
2018
Authors are greatly indebted to A. Ch. Lushchik, V. Kortov, M. Izerrouken and R.Vila for stimulating discussions. This work has been carried out within the framework of the Eurofusion Consortium and has received funding from the Euroatom research and training programme 2014–2018 under grant agreement No 633053 . The views and opinions expressed herein do not necessarily reflect those of the European Commission. The calculations were performed using facilities of the Stuttgart Supercomputer Center (project DEFTD 12939 ).
Thermal annealing of radiation defects in MgF2 single crystals induced by neutrons at low temperatures
2020
Abstract Primary radiation defects in ionic solids consist of Frenkel defects – pairs of defects - anion vacancies with trapped electrons (F-type centers) and interstitial ions. Upon temperature increase after irradiation, the electronic F-type centers are annealed due to recombination with mobile interstitials. Analysis of the recombination (annealing) kinetics allows us to obtain important information on the interstitial migration. At high radiation doses more complex dimer (F2-type) centers are observed in several charge states, which are well distinguished spectroscopically. We analysed here available experimental kinetics of the F2-type center annealing in MgF2 in a wide temperature ra…
Heavy Ion Induced Degradation in SiC Schottky Diodes : Bias and Energy Deposition Dependence
2017
Experimental results on ion-induced leakage current increase in 4H-SiC Schottky power diodes are presented. Monte Carlo and TCAD simulations show that degradation is due to the synergy between applied bias and ion energy deposition. This degradation is possibly related to thermal spot annealing at the metal semiconductor interface. This thermal annealing leads to an inhomogeneity of the Schottky barrier that could be responsible for the increase leakage current as a function of fluence. peerReviewed