Cascade Damage in the Ordered Alloy Ni3AI

1994 ◽  
Vol 373 ◽  
Author(s):  
Tho X. Bui ◽  
I.M. Robertson ◽  
M. A. Kirk
Keyword(s):  
Dislocation Loop ◽  
Room Temperature ◽  
Zone Size ◽  
Thermal Spike ◽  
Ion Energy ◽  
Vacancy Loops ◽  
Transmission Electron ◽  
Ion Energies ◽  
Average Size ◽  
Cascade Damage

AbstractThe damage (disordered zones and vacancy loops) produced in the ordered alloy Ni3AI by irradiation with different ions (Ar+, Kr+, Xe+), ion energies (30 and 50 keV), and at 30 and 300 K has been investigated by using transmission electron microscopy. At room temperature and at constant ion energy, the average size of the disordered zones increases as the ion mass increases from Ar+ to Kr+and to Xe+ ions. This trend is opposite to that of the collisional volume which decreases with increasing ion mass and highlights the importance of the thermal spike in causing disorder. At room temperature and at constant ion mass, the zone size increases with increasing ion energy. At 30K, for the same ion mass and ion energy, the size of the disordered zones is smaller than at room temperature. At both irradiation temperatures, the dislocation loop yield increases with increasing ion energy and ion mass. The loop yield was lower for irradiations at 30K compared to at 300 K. Comparison of the dislocation loop yield and the size of the disordered zones indicates that the probability for forming a loop increases with the size of the disordered zone.

scholarly journals Ion-Irradiation-Induced Amorphization Of Cadmium Niobate Pyrochlore

2000 ◽  
Vol 650 ◽  
Author(s):  
A. Meldrum ◽  
K. Beaty ◽  
L. A. Boatner ◽  
C. W. White
Keyword(s):  
Electron Microscope ◽  
Ambient Temperature ◽  
Transmission Electron Microscope ◽  
Room Temperature ◽  
Ion Irradiation ◽  
Ex Situ ◽  
Temperature Dependent ◽  
Transmission Electron ◽  
Ion Energies

ABSTRACTIrradiation-induced amorphization of Cd2Nb2O7 pyrochlore was investigated by means of in-situ temperature-dependent ion-irradiation experiments in a transmission electron microscope, combined with ex-situ ion-implantation (at ambient temperature) and RBS/channeling analysis. The in-situ experiments were performed using Ne or Xe ions with energies of 280 and 1200 keV, respectively. For the bulk implantation experiments, the incident ion energies were 70 keV (Ne+) and 320 keV (Xe2+). The critical amorphization temperature for Cd2Nb2O7 is ∼480 K (280 keV Ne+) or ∼620 K (1200 keV Xe2+). The dose for in-situ amorphization at room temperature is 0.22 dpa for Xe2+, but is 0.65 dpa for Ne+ irradiation. Both types of experiments suggest a cascade overlap mechanism of amorphization. The results were analyzed in light of available models for the crystalline-to-amorphous transformation and were compared to previous ionirradiation experiments on other pyrochlore compositions.

scholarly journals Surface Modified Ni Nanoparticles Produced by the Electrical Explosion of Wire

2015 ◽  
Vol 233-234 ◽  
pp. 513-516 ◽  
Author(s):  
A.P. Safronov ◽  
Galina V. Kurlyandskaya ◽  
S.M. Bhagat ◽  
I.V. Beketov ◽  
A.M. Murzakaev ◽  
...  
Keyword(s):  
Room Temperature ◽  
Electrical Explosion ◽  
Resonant Absorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Transmission Electron ◽  
Average Size ◽  
Surface Modified ◽  
Made In

Spherical nickel nanoparticles were prepared by the electrical explosion of wire. The as-prepared nanoparticles were modified immediately after fabrication at room temperature in order to provide tunable surface properties with focus on the development of composites filled with nanoparticles. Following liquid modificators were used: hexane, toluene and the solution of polystyrene in toluene. In one case the surface modification by carbon was made in gas phase as a result of hydrocarbon injection. The average size of the nanoparticles was about 50 nm and unit cell parameters were close to 0.351 nm. Detailed characterization was done by X-ray diffraction, transmission electron microscopy, and magnetization measurements. Sphericity was also checked using microwave resonant absorption.

Synthesis of Copper Nanoparticles at Room Temperature Using Hydrazine in Glycerol

2013 ◽  
Vol 481 ◽  
pp. 21-26 ◽  
Author(s):  
Huei Ruey Ong ◽  
Maksudur Rahman Khan ◽  
Ridzuan Ramli ◽  
Rosli Mohd Yunus
Keyword(s):  
Copper Nanoparticles ◽  
Room Temperature ◽  
Red Wine ◽  
Copper Chloride ◽  
Reduction Process ◽  
Stability Study ◽  
Ambient Conditions ◽  
Transmission Electron ◽  
Average Size ◽  
Hydrazine Solution

Copper nanoparticles (CuNPs) have been prepared by the reduction of copper chloride in glycerol using hydrazine at ambient conditions. The reduction process takes place under vigorous stirring for 8 h. The formation of CuNPs and size were confirmed by UV/Vis analysis and TEM imaging respectively. The experiment result showed that, 7.062 mM of hydrazine solution and 0.0147 mM of Cu2+ solution were needed to synthesize narrow size monodisperseCuNPs.The presence of nanoparticle was found after an induction period of 4 h and further reaction time, complete Cu0 state nanoparticle was obtained as deep red wine colour was observed. Stability study of CuNPs showed that the nanoparticles were stable up to 4 days. The particle size of the nanoparticles have been analysed by transmission electron microscopy (TEM) and the average size of CuNPs was in the range 2 to 10 nm.

1X Thin Films Prepared By Mass Separated Ion Beam Deposition

1994 ◽  
Vol 354 ◽  
Author(s):  
H. C. Hofsäss ◽  
C. Ronntng ◽  
U. Griesmeier ◽  
M. Gross
Keyword(s):  
Thermal Activation ◽  
Room Temperature ◽  
Ion Beam ◽  
Ir Absorption ◽  
Ion Energy ◽  
Ion Beam Deposition ◽  
Ion Energies ◽  
Substrate Temperatures ◽  
Absorption Measurements ◽  
Beam Deposition

AbstractWe have studied the growth and the properties of CN films prepared by deposition of mass separated 12C+ and 14N+ ions. The film thickness and density were determined as a function of ion energy between 20 eV and 500 eV and for substrate temperatures of 20 °C and 350 °C. Sputtering effects limit the maximum N concentration to about 30 - 40 at.% even for ion energies as low as 20 eV. IR absorption measurements indicate predominantly C-N and C=N bonding and an amorphous or strongly disordered CN-network. For room temperature deposited CN films with N concentrations up to 25 at.% I-V curves of metal-CN-metal devices show Frenkel-Poole behavior due to field-enhanced thermal activation of localized electrons. Films deposited at 350 °C have N concentrations below 15 at.% and graphitic properties like low resistivity and a density close to graphite.

Room Temperature Nitridation and Oxidation of Si, Ge and Mbegrown Sige Using Low Energy Ion Beams (0.1-1 Kev).

1991 ◽  
Vol 223 ◽  
Author(s):  
O. Vancauwenberghe ◽  
O. C. Hellman ◽  
N. Herbots ◽  
J. L. Olson ◽  
W. J. Tan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ion Beam ◽  
Film Properties ◽  
Dielectric Thin Films ◽  
Ion Energy ◽  
Insulating Films ◽  
Ion Energies ◽  
Energy Dependent

ABSTRACTDirect Ion Beam Nitridation (IBN) and Oxidation (IBO) of Si, Ge, and Si0.8Ge0.2 were investigated at room temperature as a function of ion energy. The ion energies were selected between 100 eV and 1 keV to establish the role of energy on phase formation and film properties. Si0.8Ge0.2 films were grown by MBE on Si (100) and transferred in UHV to the ion beam processing chamber. The modification of composition and chemical binding was measured as a function of ion beam exposure by in situ XPS analysis. The samples were nitridized or oxidized using until the N or O 1s signal reached saturation for ion doses between 5×1016 to 1×1017 ions/cm2. Combined characterization by XPS, SEM, ellipsometry and cross-section TEM showed that insulating films of stoichiometric SiO2 and Si-rich Si3N4 were formed during IBO and IBN of Si at all energies used. The formation of Ge dielectric thin films by IBO and IBN was found to be strongly energy dependent and insulating layers could be grown only at the lower energies (E ≤ 200 eV). In contrast to pure Ge, insulating SiGe-oxide and SiGe-nitride were successfully formed on Si0.8Ge0.20.2 at all energies studied.

The Microstructure of Transiently Annealed Donor Implants in GaAs

1984 ◽  
Vol 35 ◽  
Author(s):  
M.A. Shahid ◽  
R. Bensalem ◽  
B.J. Sealy
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electrical Activity ◽  
Room Temperature ◽  
Dislocation Loops ◽  
Electrical Measurements ◽  
Ion Energy ◽  
Transmission Electron

ABSTRACTUndoped SI (100) GaAs has been implanted with selenium and tin ions at room temperature at an ion energy of 300 keV and using ion dose in the range 1 × 1014 to 1 × 1015 ions cm−2. Transient annealing at 1000°C and above has been studied using electrical measurements and transmission electron microscopy. The results show that tin implanted samples have comparatively higher values of electrical activity and mobility than those implanted with selenium ions. A difference in the microstructure of these two implants was observed. Selenium implanted samples show dislocation lines and loops possessing 1/2<110> Burgers vectors while tin implanted GaAs contains dislocation loops of 1/2<110> and 1/3<111> types and also dislocation lines having 1/2<110> Burgers vectors. Both types of defect in tin implanted samples are decorated with precipitates.

scholarly journals Structural and optical investigation of CdSe quantum dots

2013 ◽  
Vol 8 (2) ◽  
pp. 83-88
Author(s):  
Neupane Dipesh
Keyword(s):  
Quantum Dots ◽  
Large Scale ◽  
Room Temperature ◽  
Spherical Shape ◽  
Cdse Quantum Dots ◽  
Optical Investigation ◽  
X Ray ◽  
Transmission Electron ◽  
Engineering And Technology ◽  
Average Size

CdSe semiconducting Quantum dots were prepared by a chemical method at a room temperature. X-ray powder diffraction and transmission electron microscope measurements conformed a hexagonal cubic crystalline phase of Cdse semiconducting Quantum dots of about 15 nm average size with nearly spherical shape. The absorption and photoluminescence spectra of the CdSe quantum dots were strongly shown blue shifted due to size quantization. The present study describes a simultaneous and highly reproducible large scale synthesis of highly luminescent CdSe Quantum dots. Kathmandu University Journal of Science, Engineering and Technology Vol. 8, No. II, December, 2012, 83-88 DOI: http://dx.doi.org/10.3126/kuset.v8i2.7329

scholarly journals Microwave-Mediated Rapid Synthesis of Gold Nanoparticles Using Calotropis procera Latex and Study of Optical Properties

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ratul Kumar Das ◽  
Punuri Jayasekhar Babu ◽  
Nayanmoni Gogoi ◽  
Pragya Sharma ◽  
Utpal Bora
Keyword(s):  
Gold Nanoparticles ◽  
Room Temperature ◽  
Spectroscopic Studies ◽  
Organic Coating ◽  
Calotropis Procera ◽  
Ftir Analysis ◽  
Spherical Nanoparticles ◽  
Transmission Electron ◽  
Crystalline Nature ◽  
Average Size

We report a microwave-mediated simple and rapid method of gold nanoparticles (GNPs) synthesis using latex of Calotropis procera. UV-Vis spectroscopic studies indicated the formation of GNPs. The GNPs were stable at room temperature (25°C) for six months. Transmission electron microscope (TEM) micrographs of the synthesized GNPs showed the formation of spherical nanoparticles with an average size of 13 ± 5 nm. SAED and XRD confirmed the crystalline nature of GNPs. Fourier transform infrared (FTIR) analysis indicated the presence of organic coating on the nanoparticles. Cytotoxicity of the GNPs was tested on HeLa and A549 and found to be nontoxic which was indicating that latex of Calotropis procera provided the nontoxic coating on GNPs, thus can be used as biomedical and pharmacological applications.

scholarly journals Plastic Flow Induced by Single Ion Impacts on Gold

1996 ◽  
Vol 439 ◽  
Author(s):  
R. C. Birtcher ◽  
S. E. Donnelly
Keyword(s):  
Plastic Flow ◽  
Gold Foil ◽  
Video Recording ◽  
Thermal Spike ◽  
Transmission Electron ◽  
Sufficient Energy ◽  
Ion Energies ◽  
Temperature Irradiation ◽  
Ion Impact

AbstractIn situ transmission electron microscopy has been used to follow room temperature irradiation of thinned bulk and 62 nm thick gold films with Xe ions in the energy range 50 to 400 keV. Energy spikes resulting from single ion impacts give rise to surface craters and holes which exist until annihilation by subsequent ion impacts. Video recording provided details with a time-resolution of 33 milliseconds. Craters were produced on the irradiated surface at all ion energies and on the opposite surface when the ions had sufficient energy to traverse the specimen. Crater sizes were as large as 12 nm for the higher energy irradiations. On average, approximately 6% of impinging ions result in craters.A single 200 keV Xe ion may produce a hole in thin gold foils. Hole formation involves the movement by plastic flow of massive amounts of material; on the order of tens of thousand Au atoms per ion impact. Individual ion impacts also result in a filling of both holes and craters as well as a thickening of the gold foil. Change in morphology during irradiation is attributed to a localized, thermal-spike induced melting, coupled with plastic flow under the influence of surface forces.

Room temperature perovskite production from bimetallic alkoxides by ketone assisted oxo supplementation (KAOS)

1996 ◽  
Vol 11 (8) ◽  
pp. 1953-1959 ◽  
Author(s):  
B.C. Gaskins ◽  
J.J. Lannutti
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Aldol Condensation ◽  
Structural Evolution ◽  
Transmission Electron ◽  
Average Size ◽  
Bimetallic Alkoxides ◽  
Barium Titanium

Barium titanate has been prepared at room temperature from a well-characterized crystalline barium titanium oxo alkoxide by reaction with acetone. An aldol condensation apparently supplies oxygen to condensing oxo alkoxide clusters. Transmission electron microscopy confirms that the crystallites so formed are dense and perfect with an average size of approximately 85 Å. Characterization of reactants and products provides a tentative understanding of structural evolution and the intermediates of the transformation. Crystalline SrTiO3 and BaZrO3 were also formed at room temperature by this same method.

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