Irradiation Cascade Threshold Energy in Gold

1970 ◽  
Vol 28 ◽  
pp. 408-409
Author(s):  
D.E. Weber ◽  
R.L. Hines
Keyword(s):  
Room Temperature ◽  
Ion Beam ◽  
Threshold Energy ◽  
Current Profile ◽  
Ion Energy ◽  
Weak Beam ◽  
Beam Image ◽  
Before And After ◽  
Uniform Current ◽  
Dose Levels

Xenon ions, Xe131, were used to bombard 200A thick, (100) single crystal gold film in a non-channeling direction at room temperature. The incident ion energy was In the 2-40 kev energy range. The ion beam had a uniform current profile which was monitored in two directions before and after the bombardment. The Ion dose levels were of order 1×1010/cm2.The resultant damage was viewed at room temperature in an Hitachi HU 11A electron microscope operated at lOOkev using 200 weak beam techniques. The micrographs of FIG. 1(a) and 1(b) are of the same area at different deviations. FIG. 1(a) represents the image of the damage at low deviation. The high deviation weak beam image is shown in FIG.

EFFECT OF ION-ENERGY ON THE PROPERTIES OF AMORPHOUS GaN FILMS PRODUCED BY ION-ASSISTED DEPOSITION

2001 ◽  
Vol 15 (28n29) ◽  
pp. 1355-1360 ◽  
Author(s):  
UDAY LANKE ◽  
ANNETTE KOO ◽  
SIMON GRANVILLE ◽  
JOE TRODAHL ◽  
ANDREAS MARKWITZ ◽  
...  
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Thermal Evaporation ◽  
Ion Beam ◽  
Atomic Ratio ◽  
Nuclear Reaction Analysis ◽  
Ion Energy ◽  
X Ray ◽  
Nitrogen Ions ◽  
Nitrogen Ion

Amorphous GaN films were deposited on various substrates viz. Si (100), quartz, glass, Al, stainless steel and glassy carbon by thermal evaporation of gallium in the presence of energetic nitrogen ions from a Kaufman source. The films were deposited at room temperature and 5 × 10-4 mbar nitrogen partial pressure. The effect of a low energy nitrogen ion beam during the synthesis of films was investigated for energies 40 eV and 90 eV. The N:Ga atomic ratio, bonding state, microstructure, surface morphology, and electrical properties of the deposited a-GaN films were studied by different characterisation techniques. The films are found to be X-ray amorphous in nature, which is confirmed by Raman spectroscopy. Rutherford Backscattering Spectroscopy (RBS) and Nuclear Reaction Analysis (NRA) indicate the N:Ga atomic ratio in the films. The 400-750 eV energy range is thought to be optimal for the production of single-phase amorphous GaN . The effect of ion-energy on optical, Raman, and electrical conductivity measurements of the films is also presented.

Defects and AlSb Precipitate Nucleation in Laser Irradiated Aluminum

1981 ◽  
Vol 4 ◽  
Author(s):  
P. S. Peercy ◽  
D. M. Follstaedt ◽  
S. T. Picraux ◽  
W. R. Wampler
Keyword(s):  
Room Temperature ◽  
Laser Energy ◽  
Ion Beam ◽  
Threshold Energy ◽  
Single Pulse ◽  
Temperature Profiles ◽  
Beam Analysis ◽  
Slip Deformation ◽  
Precipitate Nucleation ◽  
Substrate Temperatures

ABSTRACTLattice defects and precipitates induced in unimplanted and Sb-implanted <110> single crystal Al by single pulse irradiation with a Q-switched ruby laser were studied using ion beam analysis and electron microscopy. The absorbed laser energy during irradiation is directly measured in these studies to allow precise numerical modeling of the melt times and temperature profiles. For unimplanted Al, slip deformation gives rise to increased channeled yields throughout the analyzed depth and occurs for energies well below the melt threshold energy of 3.5 J/cm2. Slip deformation is also observed for irradiation energies above the melt threshold energy, and melting is accompanied by a discontinuous increase in the minimum channeling yield, X min- Implanted Sb (to ∼2 at.% peak concentrations) is found to impede epitaxial regrowth and result in polycrystalline Al formation for laser energies such that the melt front is believed not to penetrate through the Sb-containing region. For deeper melt depths, a metastable alloy is formed with up to 35% of the Sb located in substitutional sites. AlSb precipitate formation in the melt was not observed for room temperature irradiations; however, randomly oriented AlSb precipitates are observed for irradiation at substrate temperatures of 100 and 200 °C These measurements yield an estimated time for nucleation of AlSb precipitates in molten Al of 5 nsec < tnuc < 25 nsec.

Weak beam image of a superlattice dislocation in deformed Ni3 (AlHfB)

1990 ◽  
Vol 48 (4) ◽  
pp. 476-477
Author(s):  
X. F. Wu
Keyword(s):  
Dislocation Structure ◽  
Room Temperature ◽  
Deformation Behaviour ◽  
Temperature Deformation ◽  
Superlattice Dislocation ◽  
Weak Beam ◽  
Beam Image ◽  
Spark Erosion ◽  
Work Hardening Rate ◽  
Increasing Temperature

A number of intermetallic compounds with the L12 structure exhibit a strange increase in the flow stress and work-hardening rate with increasing temperature. Despite the success of some model in explaining macroscopic properties, the detailed dislocation processes of model that are assumed to take place have not been observed in microscope. This work is an attempt to determine how the dislocation fine structure is related to the deformation behaviour of L12.Single crystal Ni-23Al-1Hf-0.1B(at%) was used in the present study. direction was chosen as compression axis. Samples were deformed to plastic strain of 6%, specimens were cut parallel to by spark erosion. Fined electropolishing was donein solution of 1% perchloric acid in methanol at −50°c and 30V. The g/3g diffraction condition used in weak beam observation.Fig1 shows the dislocation structure in foil. Long fairly straight screw dislocations with b=a[011] are imaged. The formation of dipoles is regarded as a characteristic and unusual feature of the dislocation structure. This indicates that annihilation is difficult at room temperature deformation. Weak beam images of superlattice dislocations are shown in fig.2 by using different reflections. The dislocation CC is long straight screw dislocation.

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.

The Importance of Self-Sputtering by Low Energy Ions in Partially Ionized Beam Deposition

1989 ◽  
Vol 157 ◽  
Author(s):  
P. Bai ◽  
CH. SteinbrÜChel ◽  
T.-M. Lu
Keyword(s):  
Film Growth ◽  
Ion Beam ◽  
Threshold Energy ◽  
The Self ◽  
Ion Energy ◽  
Sputtering Yield ◽  
Partially Ionized ◽  
Low Energy Ions ◽  
Deposition Techniques ◽  
Beam Deposition

ABSTRACTIn ion-assisted deposition techniques such as partially ionized beam deposition, ions derived from the depositing material itself concurrently bombard the surface during thin film growth. The ion percentage in the deposition beam ranges from less than 0.1% to 100% (Ion Beam Deposition) with the ion energy varying between a few eV and several keV. When the sputtering yield of the self-sputtering is greater than one, there is a critical ion percentage, for a given ion energy, above which no net deposition can be obtained. The self-sputtering yield is shown to have a square root dependence on the ion energy above the threshold energy by fitting the experimental data obtained from the literature. The critical ion percentage for Al, Cu, Au, Ag, and C is then calculated and plotted as a function of the ion energy so that deposition and no-deposition regions are illustrated in terms of the ion energy and ion percentage.

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.

Infrared-Photovoltaic Responses of Ion-Beam Synthesized β-FeSi2/n-Si Heterojunctions

1999 ◽  
Vol 607 ◽  
Author(s):  
Yoshihito Maeda ◽  
Kenji Umezawa ◽  
Kiyoshi Miyake ◽  
Kenya Ohashi
Keyword(s):  
Room Temperature ◽  
Interband Transition ◽  
Ion Beam ◽  
Photovoltaic Cells ◽  
Threshold Energy ◽  
Surface Recombination ◽  
Wavelength Region ◽  
Pronounced Increase ◽  
Surface Recombination Rate ◽  
Trap Levels

AbstractPhotoresponses of photovoltaic cells using ion-beam synthesized (IBS) polycrystalline p+-β-FeSi2/n-Si heterojunctions were examined in an infrared (IR) wavelength region. At room temperature, an evident photoresponse due to an internal photoemission from trap levels in β-FeSi2 with the threshold energy Φ=0.62 eV was observed at 0.6-0.87 eV. The pronounced increase of a photoresponse corresponding mostly to an interband transition in β-FeSi2 was observed at 0.87-1.1 eV. The maximum dominated by a surface recombination process appeared around ∼1.2 eV. The surface recombination rate of ∼104 cm/s was estimated. The quantum efficiency was ∼60 % in the 0.8-1.0 µm wavelength region and ∼14 % around the band-gap of βFeSi2.

Room Temperature Growth of Silicon Dioxide Using a Low Energy Ion Beam

1986 ◽  
Vol 75 ◽  
Author(s):  
S. S. Todorov ◽  
E. R. Fossum
Keyword(s):  
Silicon Dioxide ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Film Growth ◽  
Ion Beam ◽  
Silicon Surfaces ◽  
Ion Energy ◽  
Thermally Driven ◽  
Thin Oxide Films ◽  
Substrate Temperatures

AbstractUltra-thin films of silicon dioxide are formed on silicon surfaces at room temperature by direct bombardment with an oxygen-containing ion beam at energies of 150 eV or less. The process of film growth is studied.through ellipsometric measurements of their properties as a function of ion energy and dose, oxygen partial pressure and substrate temperature. Typical oxide thicknesses of the order of 50 Å are obtained by three minute or longer exposures to beams of current density 135 μA/cm2. Ion-beam grown oxides are compared to conventional thin oxide films grown at elevated temperatures and show the same stoichiometry. The growth rate decreases rapidly after a continuous oxide film has been formed. Performing the ion bombardment at elevated substrate temperatures leads to only small enhancement of the oxide growth indicating non-thermally driven reaction kinetics.

Bright field and weak-beam images of dislocations gliding on (001) planes in F.C.C. metals

1978 ◽  
Vol 36 (1) ◽  
pp. 352-353
Author(s):  
H. P. Karnthaler ◽  
A. Korner
Keyword(s):  
Single Crystals ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Stage Ii ◽  
Bright Field ◽  
Weak Beam ◽  
Standard Orientation

In f.c.c. metals slip is observed to occur generally on {111} planes. Glide dislocations on intersecting {111} planes can react with each other and form Lomer-Cottrell locks which lie along a <110> direction and are sessile since they are split on two {111} planes. Cottrell already pointed out that these dislocations could glide on {001} planes if they were not split. The first study of this phenomenon has been published recently. It is the purpose of this paper to report some interesting new details of the dislocations gliding on {001} planes in pure Ni, Cu, and Ag deformed at room temperature.Single crystals are grown with standard orientation and strained into stage II. The crystals are sliced parallel to the (001) planes. The dislocation structure is studied by TEM and the Burgers vectors ḇ and glide planes of the dislocations are determined unambiguously.In Fig.l primary P and secondary S dislocations react and form composite dislocations K.

Determination of the Burgers vector of a dislocation in a Fe-Mn alloy by weak-beam image in HVEM

1978 ◽  
Vol 36 (1) ◽  
pp. 330-331
Author(s):  
Y. Ishida ◽  
H. Ishida ◽  
K. Kohra ◽  
H. Ichinose
Keyword(s):  
High Order ◽  
Simulation Technique ◽  
The Other ◽  
Image Simulation ◽  
Diffraction Vector ◽  
Burgers Vector ◽  
Weak Beam ◽  
Beam Image ◽  
Edge Component

IntroductionA simple and accurate technique to determine the Burgers vector of a dislocation has become feasible with the advent of HVEM. The conventional image vanishing technique(1) using Bragg conditions with the diffraction vector perpendicular to the Burgers vector suffers from various drawbacks; The dislocation image appears even when the g.b = 0 criterion is satisfied, if the edge component of the dislocation is large. On the other hand, the image disappears for certain high order diffractions even when g.b ≠ 0. Furthermore, the determination of the magnitude of the Burgers vector is not easy with the criterion. Recent image simulation technique is free from the ambiguities but require too many parameters for the computation. The weak-beam “fringe counting” technique investigated in the present study is immune from the problems. Even the magnitude of the Burgers vector is determined from the number of the terminating thickness fringes at the exit of the dislocation in wedge shaped foil surfaces.

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