Search results for "Recoil"
showing 10 items of 309 documents
Studies on atomic layer deposition of MOF-5 thin films
2013
International audience; Deposition of MOF-5 thin films from vapor phase by atomic layer deposition (ALD) was studied at 225-350 degrees C. Zinc acetate (ZnAc2) and 1,4-benzenedicarboxylic acid (1,4-BDC) were used as the precursors. The resulting films were characterized by UV-Vis spectrophotometry, Fourier transform infrared spectroscopy (FTIR), optical microscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), time-of-flight elastic recoil detection analysis (TOF-ERDA), isopropanol adsorption tests, and nanoindentation. It was found out that the as-deposited films were amorphous but crystallized in humid conditions at room temperature. The crystalline films h…
Corrosion Protection of Steel with Oxide Nanolaminates Grown by Atomic Layer Deposition
2011
Atomic layer deposited (ALD) aluminum and tantalum oxide (Al 2 O 3 and Ta 2 O 5 ) and their nanolaminates were applied as corrosion protection coatings on AISI 52100 steel. The aim was to combine the good sealing properties of Al 2 O 3 with the chemical stability of Ta 2 O 5 and to optimize the coating architecture in order to obtain the best possible long-term durability. Coating composition and morphology were studied with time-of-flight elastic recoil detection analysis (ToF-ERDA), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and field emission scanning electron microscopy (FESEM) and energy dispersive x-ray spectrometry (EDS). Electrochemical properties were studied with vo…
Thermal atomic layer deposition of AlOxNy thin films for surface passivation of nano-textured flexible silicon
2019
Abstract Aluminum oxynitride (AlOxNy) films with different nitrogen concentration are prepared by thermal atomic layer deposition (ALD) for flexible nano-textured silicon (NT-Si) surface passivation. The AlOxNy films are shown to exhibit a homogeneous nitrogen-doping profile and the presence of an adequate amount of hydrogen, which is investigated by Time-of-Fight Elastic Recoil Detection Analysis (ToF-ERDA). The effective minority carrier lifetimes are measured after the NT-Si surface passivation; the minimum surface recombination velocity (SRV) of 5 cm-s−1 is achieved with the AlOxNy film in comparison to the Al2O3 and AlN films (SRV of 7–9 cm-s−1). The better SRV with AlOxNy film is due …
Influence of titanium-substrate roughness on Ca–P–O thin films grown by atomic layer deposition
2013
Abstract Amorphous Ca–P–O films were deposited on titanium substrates using atomic layer deposition, while maintaining a uniform Ca/P pulsing ratio of 6/1 with varying number of atomic layer deposition cycles starting from 10 up to 208. Prior to film deposition the titanium substrates were mechanically abraded using SiC abrasive paper of 600, 1200, 2000 grit size and polished with 3 μm diamond paste to obtain surface roughness R rms values of 0.31 μm, 0.26 μm, 0.16 μm, and 0.10 μm, respectively. The composition and film thickness of as-deposited amorphous films were studied using Time-Of-Flight Elastic Recoil Detection Analysis. The results showed that uniform films could be deposited on ro…
Nucleation and growth of ZnO on PMMA by low-temperature atomic layer deposition
2015
ZnO films were grown by atomic layer deposition at 35 °C on poly(methyl methacrylate) substrates using diethylzinc and water precursors. The film growth, morphology, and crystallinity were studied using Rutherford backscattering spectrometry, time-of-flight elastic recoil detection analysis, atomic force microscopy, scanning electron microscopy, and x-ray diffraction. The uniform film growth was reached after several hundreds of deposition cycles, preceded by the precursor penetration into the porous bulk and island-type growth. After the full surface coverage, the ZnO films were stoichiometric, and consisted of large grains (diameter 30 nm) with a film surface roughness up to 6 nm (RMS). T…
Aluminum oxide from trimethylaluminum and water by atomic layer deposition:The temperature dependence of residual stress, elastic modulus, hardness a…
2014
Use of atomic layer deposition (ALD) in microelectromechanical systems (MEMS) has increased as ALD enables conformal growth on 3-dimensional structures at relatively low temperatures. For MEMS device design and fabrication, the understanding of stress and mechanical properties such as elastic modulus, hardness and adhesion of thin film is crucial. In this work a comprehensive characterization of the stress, elastic modulus, hardness and adhesion of ALD aluminum oxide (Al2O3) films grown at 110-300 C from trimethylaluminum and water is presented. Film stress was analyzed by wafer curvature measurements, elastic modulus by nanoindentation and surface-acoustic wave measurements, hardness by na…
Lifetime measurements of excited states in neutron-rich nuclei around 48 Ca
2009
The lifetimes of the first excited states of the N = 30 isotones 50Ca and 51Sc and the Z = 18 isotopes 44−46Ar isotopes have been determined using a novel technique that combines the Recoil Distance Doppler Shift method with the CLARA-PRISMA spectrometers in multinucleon transfer reactions. The results allow determinination of the effective charges above 48Ca and test the strength of the N = 28 magic number when moving away from the stability line. Gadea Raga, Andrés, Gadea.Andres@ific.uv.es ; Algora, Alejandro, Alejandro.Algora@ific.uv.es ; Rubio Barroso, Berta, Berta.Rubio@ific.uv.es
Gas-filled recoil separator for studies of heavy elements
1995
Abstract A gas-filled recoil separator for the study of heavy elements has been constructed. The separator is of type QDQQ with the first, vertically focusing, quadrupole providing improved matching to the acceptance of the dipole magnet. The separator has been designed also for use in vacuum mode in which case a mass resolving power of ≈ 100 is estimated. The deflection angle is 25° and the radius of curvature is 1850 mm. Maximum beam rigidity is 2.2 T m. In the first experiments, new isotopes in the region Z = 85–90 have been synthesized.
Recent applications of the JYFL gas-filled recoil separator
1997
Abstract The gas-filled recoil separator RITU at the Department of Physics, University of Jyvaskyla (JYFL) was constructed in 1992–1993, and the first experiments were performed in late 1993. RITU differs from other gas-filled separators by having a vertically focusing quadrupole magnet in front of the separating dipole for better matching with the dipole acceptance. New results from RITU include the discovery of 13 previously unpublished isotopes of At, Rn, Fr, Ra, Ac and Th, while experiments in the transuranium region have also been made. Illustrative examples from these studies together with results on background properties, efficiency of separation, and other performance data will be p…
Position sensitive plastic scintillator for beta particle detection
2022
A new segmented plastic scintillator detector Tuike has been developed for recoil-beta tagging experiments at the Accelerator Laboratory of the University of Jyväskylä. The detector consists of individual plastic scintillator bars arranged in two orthogonal layers, and the scintillation light is detected using silicon photomultipliers. Performance of the new detector was tested using fusion-evaporation reaction 40Ca(36Ar, pn)74Rb, and the results are discussed here. It was found that for beta particles seen in the main silicon detector, Tuike can tag high-energy beta particles with a 48(10)% efficiency. An energy calibration method using Compton edges of gamma ray transitions is described i…