摘要:

The retention of argon in low energy (≤ 1 keV) high fluence (≥ 1017cm−2) argon irradiated Mo and Si has been studied by Thermal Argon Desorption Spectrometry and Transmission Electron Microscopy. It is shown that high fluence argon trapping cannot be described by a linear superposition of low fluence trapping processes. This is partly due to the already known effect of gas-sputtering, but in addition there are important effects due to the development of irradiation-induced substructures. In Mo the creation of self-interstitial loop segments intersecting the surface lead to a significant increase in Ar trapping, while in Si the creation of Ar bubbles via irradiation-induced transport mechanisms is held responsible for extra trapping.

ISSN:1042-0150    

DOI:10.1080/10420158908217864

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A comparison is made of damage production in silicon, by 30 keV antimony and xenon ion bombardment for both room temperature and elevated temperature substrates as a function of ion dose. The purpose of the study is to investigate the role of any chemical effects which might modify damage retention resulting from high concentration of implanted impurity.

ISSN:1042-0150    

DOI:10.1080/10420158908217865

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Stopping powers and energy losses of 2.6-18.0 MeV7Lin+ions were measured in transmission geometry for 2.0μm Havar, 2.7μm nickel, 8.8μm Kapton, and for 3.3μm and 12.2μm Mylar foils. The experimental data were compared with calculated predictions obtained by using Bragg's addivity rule and using the Andersen-Ziegler parameters for proton stopping with appropriate scaling for lithium ions. The present stopping power data for nickel agree well with the scarce values available in the literature. For the composite foils no previous data may be found. Distinct disagreement between the present results and calculated predictions was observed in all cases.

ISSN:1042-0150    

DOI:10.1080/10420158908217866

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Lithium was implanted into various metals in the dose range of 1014-16ions/cm2and at 50 to 300 keV. Depth distributions of lithium are recorded with a special nuclear reaction technique of extreme sensitivity, and the profile moments are deduced.

ISSN:1042-0150    

DOI:10.1080/10420158908217867

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Climb sources emitting dislocation loops have been observed in both Cu-10% Ni and Cu-50% Ni alloys during irradiation with 1 MeV electrons in a high voltage electron microscope (HVEM). In Cu-10% Ni, the sources emit rectangular loops with a(100) Burgers vectors and {100} habit planes and prismatic loops with a/2(110) Burgers vectors. In Cu-50% Ni, however, the sources emit only a/2(110) loops: no rectangular a(100) loops were observed. The difference is suggested to be due to both the stacking fault energy, which controls the stability of the a(100) dislocations, and to the intrinsic structures of the sources.

ISSN:1042-0150    

DOI:10.1080/10420158908217868

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Radiation damage in InSb as a result of the implantation of helium ions, has been investigated. The results of transmission electron microscopic investigations of InSb samples implanted at different temperatures are presented. The observed radiation damage varied from a slight increase in the dislocation density as a result of heated implantations, to the total loss of crystallinity after implantation at 77 K. The nature of the dislocation loops which form due to room temperature implantation, was determined. The relation between the TEM observations and RBS/channeling results, as well as the development of radiation damage in InSb due to light ion irradiation, are also discussed.

ISSN:1042-0150    

DOI:10.1080/10420158908217869

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Glass formation and crystal structure retainment in ion irradiated alloys are interpreted on the basis of collision cascade development and bombardment induced compositional changes. Local charge transfer reactions schematize atomic interactions giving rise to glassy or crystalline nuclei. Qualitative differences exist between amorphous and crystalline transition metal based alloys.

ISSN:1042-0150    

DOI:10.1080/10420158908217870

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The (p,p') reaction with a pulsed proton beam has been used in in-beam TDPAD measurements to excite and recoil implant19F ions into various carbon allotropes (single and polycrystalline graphite and vitreous and colloidal carbon). Spin rotationR(t) spectra generated from delayed time spectra of the19F 197 keV gamma ray show that the implants take up two characteristic residence sites in the host samples. One site is sharply defined (low spreadδ), and has a quadrupole coupling frequency ofvq= 57 MHz; the other, of lowervq, is more diffuse (largeδ). The parameters of the electric field gradients at the two implant sites in the carbon allotropes are compared with similar measurements on19F in diamond, Si and Ge hosts, and in several F-C compounds.

ISSN:1042-0150    

DOI:10.1080/10420158908217871

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Self-diffusion data on amorphous metallic alloys determined in long-time radio-tracer experiments and activation-enthalpy spectra deduced from short-time structural relaxation studies on such materials are reviewed and analyzed in terms of current random transition rate models. It is shown that the seeming discrepancy between the self-diffusion enthalpies and the comparatively small enthalpies obtained from measurements of the magnetic after-effect arises from the existence of activation-enthalpy spectra. Whereas the short-time experiments reveal the small-activation-enthalpy parts of these spectra, the long-time self-diffusion experiments are controlled by the larger activation enthalpies. Assuming that the activation-enthalpy distributions are Gaussian, their characteristic parameters have been determined by comparing the two types of measurements. It is shown that the Arrhenius-type diffusion coefficients found by experiment are compatible with half-widths of the activation-enthalpy spectra of about 0.3 eV. Based on an analysis of the pre-exponential factors and other typical properties of the diffusion coefficients, potential mechanisms of the diffusion in amorphous alloys are proposed.

ISSN:1042-0150    

DOI:10.1080/10420158908217872

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The ESR of self-trapped excitons (STE) in KI, RbI and CsI has been measured by detecting a change of the recombination luminescence induced by the 35 GHz resonant microwave. The zero-field splittingDin the triplet states which emit the luminescence peaked at 3.3 eV in KI, 2.3 eV in RbI and 3.7 eV in CsI is obtained to be D/g∥β=7.3, 11 or 14 and 48 kG, respectively. The half-width of the ESR lines for KI, RbI and CsI is determined to be 9.0, 2.5 and 4.0 kG. It is proposed that the vibronic structure of the STE related to the 3.3 eV band is characterized by a diffused orbit of a trapped electron, softened surrounding lattice and smaller relaxation inside the core in comparison with the STE in KCl. Adopting the Stokes shift of the luminescence as a measure of the stability of STE, the structures of the STE in alkali bromides and iodides are checked in view of a STE centered on a halogen ion site.

ISSN:1042-0150    

DOI:10.1080/10420158908217873

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor