摘要:

Stopping power measurements have been made for ZnTe and CdTe for protons and α-particles over the energy range 500-2800 keV. Results were derived from transmission energy losses in thin films. Comparisons with theoretical and other experimental data are made. Proton energy straggle values in ZnTe and CdTe have also been obtained. They appear constant over the energy range investigated.

ISSN:0033-7579    

DOI:10.1080/00337577708233105

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The radiation damage caused by the implantation of 300 keV Xe and Cd ions into InSb was measured by means of the channeling technique using an 800 keV4He beam. The disorder caused by room temperature implantations was measured as a function of (a) the implantation dose, (b) the implantation dose rate, and (c) the implantation direction with respect to the crystal axis. It was found that the damage in InSb reaches the random level at doses which depend on the implantation conditions. The fact that the “amorphous” level could be reached as a result of heavy ion implantation into InSb fits well with the monotonic dependence of the damage-saturation on ionicity observed for other semiconductors. A previous discrepancy with the ionicity model which existed for InSb damaged with Bi ions is thus removed. Low dose rate (4 nA/cm2) implantations and implantations alone a major crystalline axis ((111)) were found to cause less damage with different profiles than did high dose (40 nA/cm2) or random direction implantations, indicating that the mechanisms responsible for the creation of the stable damage complexes depend on the implantation conditions. While the damage seems to increase linearly with the dose for the high flux implanation, its dependence on the dose for low flux implantation seems to increase only as the square root of the dose, in agreement with Chadderton's model which assumes different damage nucleation processes for different dose rates.

ISSN:0033-7579    

DOI:10.1080/00337577708233106

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The internal friction and sheer modulus of polycrystalline Al + (0.2, 0.7, 2 and 4) at % Ga was measured as a function of temperature, using measurements of logarithmic decrement and frequency of free sample vibration. The internal friction curves for the smaller solute concentrations went through a maximum (peak) at 230 K. The height of the peak increased initially with solute concentration, then disappeared at higher concentrations. This peak is probably due to the interaction of solute atoms with dislocations.

ISSN:0033-7579    

DOI:10.1080/00337577708233107

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The dechanneling of H+in the perfect (100) channel and the (100) channel containing displaced atoms in KCl were calculated by solving diffusion equation, for several temperature and incident energies. Two typical positions of the displaced atoms were treated: one displaced by 7aand the other by 3atowards the center of the channel, whereais the Thomas Fermi radius and is 1/13 of the distance between the center and the string. It was shown that the difference Δχ between the dechanneled fraction in channels with and without displaced atoms for the displacement of 7adepends on energy,E, and temperature,T, asE−1andT1respectively, while the energy and temperature dependences of Δχ for the displacement of 3aare much weaker. It was pointed out that these differences in the energy and temperature dependences are indicative of the difference in the dechanneling in crystals involving interstitial type defects and that in crystals in which lattice is distorted. The experimental results reported in the literatures were discussed in view of the result of the present calculation.

ISSN:0033-7579    

DOI:10.1080/00337577708233108

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The growth of point defect aggregates during irradiation, i.e. in the presence of supersaturation in both vacancies and interstitials, is considered as a random walk problem and shown to be amenable to analytical solution with physically reasonable assumptions. The model applies as long as direct interaction between aggregates can be ignored.

ISSN:0033-7579    

DOI:10.1080/00337577708233109

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The surface of ion implanted silicon may exhibit various bright colours when implanted under particular high dose conditions. For some scanning systems these colours may be in the form of distinct colour bands. The mechanism of colour generation is explained. The observed colour is shown to be related to the existence and thickness of an amorphous silicon layer created by the implantation process. Different colour generation mechanisms apply when the amorphous layer is buried and when it is continuous to the surface. The colour generation model explained shows that the commonly observed “milkiness” condition, often associated with amorphous threshold determination, is a special case of surface colour generation in ion implanted silicon.

ISSN:0033-7579    

DOI:10.1080/00337577708233110

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The elastic after-effect of Mo single crystals with various orientations were measured after fast neutron irradiation at about 5 K. Two prominent relaxations were observed at 8 K and 26 K (at relaxation time ≈2 min). These two relaxations correspond, respectively, with the 12 K and 39 K peaks in previous high frequency experiments (at vibrational frequencies ≈500 Hz). The 26 K relaxation was found to be about 2.5 times larger in strength than that expected from the unstable 39 K peak observed in the high frequency measurements. The 8 K and 26 K relaxations annealed out in the recovery stages I (∼28 K) and IIa (∼42 K), respectively. Their dependence on irradiation fluence and orientation and their independence on pre-irradiation deformation and/or doping indicate that these relaxations are caused by intrinsic point defects, in good agreement with observations in the high frequency measurements. The origins of these two relaxations are considered to be a stress-induced rotation of free (110) split-type self-interstitials (8 K relaxation) and, possibly, of di-interstitials (26 K relaxation), respectively.

ISSN:0033-7579    

DOI:10.1080/00337577708233111

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Investigations are reported of the changes in TL sensitivity in crystalline quartz induced by varying doses of protons and γ-rays. The sensitivity is seen at first to increase and then (with proton irradiation) to show a marked decrease as larger doses are imparted to the sample. This effect is interpreted as being caused by damage to the Al/alkali recombination centre.

ISSN:0033-7579    

DOI:10.1080/00337577708233112

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Changes in the distribution of Manganese solute in a 99.8% pure nickel crystal after 75 keV Ni+ion bombardment are reported. Irradiations were performed at 23°C and 500°C at a maximum damage rate of 0.046 dpa/s. The depth profiles of solute impurities near the surface were measured by simultaneous sputter-profiling and Secondary Ion Mass Spectrometry. The results are interpreted in terms of a model of the diffusion and interaction of vacancies, divacancies and self-interstitials. Solute redistribution at 500°C and 23°C is found to be due to the effects of di-vacancy and interstitial fluxes respectively. The relationship of the solute profiles to the point defect distributions is discussed.

ISSN:0033-7579    

DOI:10.1080/00337577708233113

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

When the surface of a solid is bombarded with ions a fraction of the primary energy is reemitted by ion reflection and sputtering. The contribution of ion reflection or sputtering to energy reflection is determined by the mass ratio of the bombarding ions to the target atoms.1,2In the case of light ions the contribution of reflected ions is dominant. Results for He+and Ne+bombardment were described in a previous paper.3The present paper deals with results for Ar+, Kr+, and Xe+bombardment of the same targets as investigated before.3The energies of the mass selected bombarding ions range from 9 to 16 keV. The measurements were carried out by means of the thermic detector described in a separate paper.4For the given mass ratios most of the reemitted energy is related to sputtering.

ISSN:0033-7579    

DOI:10.1080/00337577708233114

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor