摘要:

Characterization of single-crystal and plasma-sprayed spinels before and after Ar+-ion irradiation was performed by XPS and RBS techniques. Two Olsand Mg2ppeaks were observed in both spinels, respectively, and the second peaks were observed at the positions of higher energies than those in unirradiated spinel. In the Ar+-ion irradiated plasma-sprayed spinel, Olspeak with higher energy was observed predominantly. Two Al2ppeaks were observed in Ar+-ion irradiated single-crystal spinel whereas only one Al2ppeak was observed in Ar+-ion irradiated plasma-sprayed spinel. It is indicated from these results that plasma-sprayed spinel is easily amorphized by Ar+-ion irradiation, compared with single-crystal spinel.

ISSN:0033-7579    

DOI:10.1080/00337578608226014

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

In-beam measurements of the radiation induced conductivity in MgO have enabled one to separate the intrinsic from the impurity induced conductivity. The intrinsic conductivity varies directly with dose rate from < 103to 109rad h−1. The impurity sensitive conductivity is related to the iron content through the induced electron trapping centres.

ISSN:0033-7579    

DOI:10.1080/00337578608226015

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Aluminum oxide was implanted with bromine and subsequently annealed at temperatures between 800 and 1500°C in a reducing atmosphere. Changes in the lattice damage and the impurity distribution were monitored by Rutherford backscattering and channeling (RBS-C) techniques. Changes in the topography were monitored by optical and secondary electron microscopy. The implantation resulted in the formation of an “amorphous” surface layer. Upon annealing, the bromine segregated to form bubbles which blistered releasing 90% of the bromine from the Al203matrix.

ISSN:0033-7579    

DOI:10.1080/00337578608226016

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

We report on the use of high resolution electron microscopy and optical processing techniques to study defects in solid inert gas precipitates (bubbles) formed by ion implantation into aluminium. Faceted precipitates, of the order of 5 run in length and epitaxial with the aluminium, in some cases exhibit a high degree of crystalline perfection but in others departure from the regular atomic arrangement is evident in the lattice images. Optical processing techniques have been applied to enhance the lattice images and in some cases to colour encode the aluminium and inert gas spacings present in the micrograph, with the aim of indentifying specific defect structures in the inert gas solid. We demonstrate that the solid “bubble”, formed in a metal by ion implantation, provides a means of studying defects in a simple insulator, the rare gas solid.

ISSN:0033-7579    

DOI:10.1080/00337578608226017

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The structures of diamonds implanted with B and N ions have been studied by EPR and electron diffraction. The relationship between the spin density and the dose implanted is given and electron diffraction patterns are shown. The results of EPR and electron diffraction experiments show that the structure of diamond will be changed as implanted dose increases. The amorphous form of diamond can be formed when the doses are equal to and larger than 1–3 × 1015N+/cm2. The wear resistance of diamonds implanted at certain dose will be increased.

ISSN:0033-7579    

DOI:10.1080/00337578608226018

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Modifications to the mechanical properties of ceramic surfaces by ion implantation have been investigated as a means of producing increased wear resistance for tribological applications. It has been established that ion implantation can result in a number of tribologically relevant parameters (e.g. hardness and indentation fracture toughness) being modified in various ways. Examples of these changes will be given for ion implanted sapphire. Further, these modifications have been related to critical structural changes occurring in or near the surface. Radiation damage, amorphisation and surface stress generation are the most important of these and affect both hardness and indentation fracture behaviour. This paper will describe how the observed mechanical properties are related to the structural changes occurring in the surface and presents a number of criteria designed to enable prediction of the mechanical property modifications that will ensure after implantation of a given substrate with a given ion. These include the application of a bond-type criterion to determine the amorphisation dose (amorphisation critically affecting mechanical properties) and an elasticity criterion to determine the maximum likely implantation induced surface stress.

ISSN:0033-7579    

DOI:10.1080/00337578608226019

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Irradiation damage studies of lithium oxide (Li20) using optical absorption and electron spin resonance (ESR) methods are reviewed. F+-centers and the defects associated with F aggregate centers were introduced in Li2O irradiated with thermal neutrons and oxygen ions. In addition, colloidal Li metal centers were produced at the high fluences. The production process of the F+-centers was discussed from results of the oxygen-ion irradiation. The recovery behavior of F+-centers was studied by isochronal and isothermal annealing experiments.

ISSN:0033-7579    

DOI:10.1080/00337578608226020

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Transmission electron microscopy has been used to study Be+ion implantation following encapsulation and transient annealing of GaAs. The Be+implanted GaAs stays crystalline and contains faulted and unfaulted loops. Deposition of CVD Si3N4at 635°C does not change the defect density significantly. A 30 s anneal at 900°C removes the faulted loops and crystallinity is improved. Precipitates which may be due to beryllium are formed during this anneal.

ISSN:0033-7579    

DOI:10.1080/00337578608226021

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

For special implantation conditions (light ions, sufficiently high implantation temperatures in the case of heavier ion masses) defects are created in GaAs, the back-scattering minimum yield of which does not show a pronounced direct backscattering part.

ISSN:0033-7579    

DOI:10.1080/00337578608226022

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Polycarbonate films are widely used as solid state track detectors (SSTDs) of radiation, but as yet our knowledge of the microscopic nature of the latent track is limited. The processes of chemical etching and thermal annealing are not fully understood. The lack of stability of track parameters bears on the accuracy of the charge determination of energetic heavy nuclei.

ISSN:0033-7579    

DOI:10.1080/00337578608226023

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor