摘要:

It is shown experimentally as well as theoretically that sputtering spot patterns of single crystals can seriously be influenced by the condensation process on the collector. This results in erroneous representation of the preferential emission regarding both the ejection characteristic and the intensity ratio of different ejection directions.

ISSN:0033-7579    

DOI:10.1080/00337577408241453

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The intensity distribution of 1 MeV positrons and electrons scattered by the single atomic row and in the three-dimensional Au structure are calculated with the use of the classical model of binary collisions. The main features of the positively and negatively charged particles motion are discussed in terms of the continuum approximation of particle channelling. For the positively charged particles the qualitative agreement with the experimental data was achieved. For the negatively charged particles motion in the crystal lattice the lack of the statistical randomization of the transverse momentum vector was demonstrated.

ISSN:0033-7579    

DOI:10.1080/00337577408241454

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The nature of trapping and emission centres in various impurity doped BaSO4phosphors has been investigated by thermoluminescence (glow curves and emission spectra) and esr techniques. The results indicate that anion radicals (such as SO4−, SO3−, O3−etc) that act as trapped hole centres are formed by γ-irradiation. It has been found that corresponding to the temperatures at which the above centres are annihilated there are glow peaks in the TL curves. It is, therefore, suggested that the thermally released holes from each of such centres are mobile and recombine at some trapped electron centres. The energy thus released excite the impurity ion present, which on returning to the normal state gives its characteristic emission.

ISSN:0033-7579    

DOI:10.1080/00337577408241455

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

A study is made of the effect of fast neutrons on the electrical conductivity and thermoelectric power and also the neutron-induced defects in β-Ga2O3. It is found that the conductivity decreases while the thermoelectric power increases after an irradiation of about 1017nvt. This is explained by assuming that the defects introduced into the Ga2O3lattices act as trapping centres for electrons. The defect anneal by thermally activated processes at temperatures up to about 1000 °K with an activation energy of about 2 eV. The defects are the most likely vacancies of the galium atoms.

ISSN:0033-7579    

DOI:10.1080/00337577408241456

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Prismatic dislocation loops were observed to emanate from a gas bubble in neutron-irradiated aluminum-lithium alloy during electron irradiation at 200°C in a 200 kV electron microscope. The loops aligned in the ⟨110⟩ directions were analysed to be vacancy loops on ⟨111⟩ plane witha/2 ⟨110⟩ Burgers vector. In a 1000 kV electron microscope, the prismatic punching were observed to occur during electron irradiation at 50°C. The prismatic loops were considered to nucleate at the surface of a gas bubble by condensation of radiation-produced vacancies and to propagate in the ⟨110⟩ directions by pencil glide under vacancy supersaturated environment.

ISSN:0033-7579    

DOI:10.1080/00337577408241457

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The stopping cross sections of Hc ions in bismuth, lead and tungsten have been measured at incident energies from 0.4 MeV–1.9 MeV. The energy losses of helium ions in mcuum evaporated films of bismuth and lead and sputtered films of tungsten were determined using a backscattering technique. Atomic areal densities were measured by a microbalance technique for the bismuth and lead films. The thicknesses of the tungsten films were determined by multipbbeam interferometry and a density of 0.93X atomic density was assumed in order to evaluate the areal density. Brice's three parameter formula has been fit to the data. Comparison of the results has also been made with the semi-empirical calculations and the experimental results of Chu.et al., and those of Lin,et al.

ISSN:0033-7579    

DOI:10.1080/00337577408241458

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Velocity selected beams of atoms and molecules have been produced by sputtering from various alkalihalide surfaces under 6 keV Ar+ion bombardment. The mass spectrum and the velocity distribution of these particles have been analysed in the range from 0-1 3000 m/s. In the low velocity part of the spectrum monatomic particles as well as polyatornic ones have been found. For velocities larger than 3000 m/s the number of sputtered molecules is very small compared to the number of atoms. In addition to typical sputtering velocity distributions, thermal distributions are also found, due to vaporization of the less effectively sputtered atoms from the crystals. Above a few eV the energy distribution of a given alkali or halogen atom is independent of the target from which it is sputtered. There are indications that some sputtered atoms and molecules are formed in long lived excited states.

ISSN:0033-7579    

DOI:10.1080/00337577408241459

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The helium stopping cross section in Zinc Telluride was measured for energies varying from 300 keV to 2 MeV. Up to an energyEα ≃ 600 keV,dE/dxis not far fromkE1/2(LSS theory). Values given by the BETHE theory were reached only forEα > 1.6 MeV. By a “bursting” method the projected range was also measured and the values are in accordance with those computed from the experimental data ofdE/dx.

ISSN:0033-7579    

DOI:10.1080/00337577408241460

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The effect of a pinning of dislocation on the internal friction and modulus defect is discussed for the two types of interaction between dislocation and point defect, the one being the interaction with viscous dragging force (the defect dragging model by Simpson and Sosin (1972)) and the other the interaction with elastic restoring force. The mode of a dislocation motion when a pinning occurs at a center of a dislocation loop is examined and the anomaly in the change in the modulus defect in these models is discussed.

ISSN:0033-7579    

DOI:10.1080/00337577408241461

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Simple defects created by electron irradiation ofn-type germanium at 85°K were studied by electrical measurements in the temperature range of 80-300°K. The annealing processes observed were found to be strongly dependent upon the electron energy. These results provide new evidence for the tentative divacancy-interstitial model of defects created which explains their temperature transformation at 200°K.

ISSN:0033-7579    

DOI:10.1080/00337577408241462

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor