RBS/Channeling Diffusion Studies of High Energy Au Implanted Mg Single Crystals

1991 ◽  
Vol 235 ◽  
Author(s):  
R. C. Da Selva ◽  
M. F. Da Silva ◽  
L. Thomé ◽  
A. A. Melo ◽  
J. C. Soares
Keyword(s):  
Single Crystals ◽  
Temperature Regime ◽  
High Energy ◽  
Back Diffusion ◽  
Thermally Activated ◽  
Diffusion Studies ◽  
Higher Temperature ◽  
Diffusion Behaviour ◽  
Thermally Activated Process

ABSTRACTRBS/channeling analyses of high energy Au implantation into Mg are presented. The diffusion behaviour of Au was studied and the occurrence of essentially two distinct regimes were observed: the segregation regime at lower temperatures correlated with the damage introduced by the high energy implantation and the higher temperature regime as a normal thermally activated process of back-diffusion.

Mechanical Loss Associated with Stress Anomaly in Ni3Al and Ni3(Al, Ta) Single Crystals

1999 ◽  
Vol 578 ◽  
Author(s):  
E. Carreno-Morelli ◽  
B.L. Cheng ◽  
M. Demura ◽  
R. Schaller ◽  
N. Baluc ◽  
...  
Keyword(s):  
Single Crystals ◽  
Oscillation Amplitude ◽  
Relaxation Peak ◽  
Octahedral Plane ◽  
Mechanical Loss ◽  
Positive Dependence ◽  
Thermally Activated ◽  
Temperature Regimes ◽  
Two Temperature ◽  
Thermally Activated Process

AbstractThe mechanical loss and shear modulus behaviors of Ni3Al and Ni3(Al, Ta) single crystals have been investigated in the temperature range 100 K – 1300 K. The mechanical loss spectra exhibit two temperature regimes, which are separated by a relaxation peak at nearly 950 K for a frequency of 1 Hz. This relaxation peak has been interpreted by the stress re-orientation of Al-Al elastic dipoles in the (111) octahedral plane [1, 2]. In the low temperature regime, corresponding to the anomaly domain of the flow stress, the mechanical loss of pre-deformed specimens exhibit a strong positive dependence on both the oscillation amplitude and the amount of pre-strain.Pre-deformations, which were performed either at room temperature or at 100 K, yield a broad maximum in the mechanical loss that extends from nearly 100 K up to 550 K. This maximum is observable for only strain amplitudes larger than 10−4 and entirely vanishes after heating the specimens above 550 K. The increase in mechanical loss has been attributed to the bowing of the superkinks under the action of the applied stress. The gradual and irreversible decrease in damping above 300 K is interpreted in terms of pinning of the screw dislocation segments by a thermally activated process leading to the formation of Kear-Wilsdorf locks.

Variable Temperature Measurement on Operating Pentacene-Based OTFT

2008 ◽  
Vol 1091 ◽  
Author(s):  
Hung-Keng Chen ◽  
Po-Tsun Liu ◽  
Ting-Chang Chang ◽  
S.-L. Shy
Keyword(s):  
Conduction Mechanism ◽  
Variable Temperature ◽  
Electrical Measurement ◽  
Isokinetic Temperature ◽  
Trap States ◽  
Band Tail ◽  
Thermally Activated ◽  
Multiple Trapping ◽  
Higher Temperature ◽  
Release Model

AbstractVariable temperature electrical measurement is well-established and used for determining the conduction mechanism in semiconductors. There is a Meyer¡VNeldel relationship between the activation energy and the prefactor with a Meyer¡VNeldel energy of 30.03 meV, which corresponds well with the isokinetic temperature of about 350 K. Therefore, the multiple trapping and release model is properly used to explain the thermally activated phenomenon. By the method, an exponential distribution of traps is assumed to be a better representation of trap states in band tail. Samples with higher temperature during measurement are observed to show better mobility, higher on-current and lower resistance, which agree well with the multiple trapping and release model proposed to explain the conduction mechanism in pentacene-based OTFTs.

Electrochemical degradation of refractory pollutants using TiO 2 single crystals exposed by high-energy {001} facets

2014 ◽  
Vol 66 ◽  
pp. 273-282 ◽  
Author(s):  
Ai-Yong Zhang ◽  
Lu-Lu Long ◽  
Chang Liu ◽  
Wen-Wei Li ◽  
Han-Qing Yu
Keyword(s):  
Single Crystals ◽  
High Energy ◽  
Electrochemical Degradation

Luminescence and photoconductivity of gadolinium gallium garnet single crystals irradiated by high-energy electrons and neutrons

1993 ◽  
Vol 140 (2) ◽  
pp. 353-361 ◽  
Author(s):  
V. I. Vasyltsiv ◽  
Ya. M. Zakharko ◽  
A. O. Matkovskii ◽  
D. Yu. Sugak ◽  
S. B. Ubizskii ◽  
...  
Keyword(s):  
Single Crystals ◽  
High Energy ◽  
Gadolinium Gallium Garnet ◽  
High Energy Electrons

Computersimulation der Rückstreuung schneller schwerer Ionen an einkristallinen (001)-und (111̅)-Goldoberflächen / Computer Simulation of the Backscattering of High Energy Ions from (001)- and (111̅)-surfaces of Au-Single Crystals

1976 ◽  
Vol 31 (3-4) ◽  
pp. 316-326 ◽  
Author(s):  
H. Schmidt ◽  
K. Güttner
Keyword(s):  
Computer Simulation ◽  
Computer Program ◽  
Single Crystals ◽  
Grazing Incidence ◽  
High Energy ◽  
Rapid Decrease ◽  
Fcc Lattice ◽  
High Energy Ions

A computer program for following the trajectories of high energy ions in an fcc-lattice has been written to evaluate the reflection rate of high energy ions with grazing incidence to (001)- and (111̅)-Au-surfaces. The calculation yields a rapid decrease of the reflection rate for penetration directions close to low-index atomic planes. It can be shown that this result is caused by channeling of the ions between the atomic planes.

Behaviour of Implanted Hydrogen in Gallium Phosphide Single Crystals

1988 ◽  
Vol 144 ◽  
Author(s):  
J. M. Zavada ◽  
R. G. Wilson ◽  
S. W. Novak ◽  
S. J. Pearton ◽  
A. R. Von Neida
Keyword(s):  
Mass Spectrometry ◽  
Single Crystals ◽  
Diffusion Coefficients ◽  
Gallium Phosphide ◽  
Secondary Ion Mass Spectrometry ◽  
Furnace Annealing ◽  
Higher Temperature ◽  
Redistribution Of Hydrogen ◽  
Secondary Ion ◽  
Post Implantation

ABSTRACTIn this paper we report on the depth distributions of implanted hydrogen in GaP crystals and the subsequent changes produced by post- implantation furnace annealing. A sulfur doped n+ GaP wafer has been implanted with 333 keV protons to a fluence of 5E15/cm+2. A similar wafer was implanted with 350 keV deuterons to the same fluence. Portions of each wafer have been furnace annealed at temperatures up to 500°C. The implanted hydrogen and the dopant S atoms were then depth profiled using secondary ion mass spectrometry (SIMS). The measurements show that the redistribution of hydrogen begins with annealing at about 300°C and proceeds both towards the surface and deeper into the substrate. The overall behavior is similar to that found previously for hydrogen in GaAs. However, in GaP crystals this redistribution begins at a higher temperature and proceeds more slowly in the implanted region. Based on the SIMS profiles, diffusion coefficients for hydrogen migrating into substrate are obtained.

scholarly journals Luminescence in KI:Tl

1961 ◽  
Vol 14 (3) ◽  
pp. 368 ◽  
Author(s):  
JE Alderson ◽  
SE Williams
Keyword(s):  
Single Crystals ◽  
High Energy ◽  
Activator Concentration ◽  
Host Crystal ◽  
Absorption Bands ◽  
High Energy Side ◽  
Luminescence Efficiency ◽  
Vacuum Monochromator ◽  
Impurity Centre ◽  
Energy Side

Freshly cleaved single crystals of KI:TI containing various concentrations of Tl have been irradiated in a vacuum monochromator in the 2800-1100 A region at temper. atures between -140 and 45 �0. The relative luminescence efficiencies in the Tl absorption bands and the host crystal fundamental absorption show that energy is transferred from host crystal to impurity centre to produce luminescence at room temperatures. To the high energy side of a threshold, which appears to depend on activator concentration, the luminescence efficiency is superlinear above about 15 �0 for KI:Tl (0�0005%).

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