摘要:

It has been established that dislocation mobilities in GaAs are reduced by In doping. This reduction operates mainly on defects exhibiting at least one α (As core) partial dislocation. We discuss here the different interactions between In and α partials which can occur. We propose interstitial In incorporated on dangling bonds as responsible for the observed reduction in mobility. The role of temperature and stress is also discussed.

ISSN:0950-0839    

DOI:10.1080/09500838908206333

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Austenitic 316L stainless steel alloys annealed at 550°C for 100 h present a few ferrite precipitates surrounded by a new interfacial phase, here called the I-phase, that develops at the level of the austenite/ferrite interface. The I-phase presents the typical patterns of an icosahedral quasicrystal with a primitive hypercubic lattice of parameter A = 0.63 nm. The marked orientation relationships between the I-phase and the ferrite precipitates strongly suggest that this phase results from a decomposition of the ferrite and not of the austenite. The I-phase is metastable and transforms eventually after annealing at 700°C to the stable crystalline σ-phase.

ISSN:0950-0839    

DOI:10.1080/09500838908206334

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The phase transformation between the tetragonal and orthorhombic phases in YBa2Cu3O7−xhas been observed byin situhigh-resolution electron microscopy and the structure of a transformation interface between the two phases has been determined directly from an analysis of the lattice fringes. It has been shown that the interface is fully coherent and broad over 50 nm, and that the lattice cells undergo a continual transition from the tetragonal phase to the orthorhombic phase. This observation is in good agreement with a model proposed by Malis and Gleiter for the ferroelectric-para-electric transformation in BaTiO3.

ISSN:0950-0839    

DOI:10.1080/09500838908206335

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Optical absorption measurements have been derived from photothermal deflection spectroscopy (PDS) and the constant photocurrent method (CPM) in the photon energy range from 06 to 1.9eV for undoped hydrogenated amorphous silicon films with thicknesses between 1.0 and 3.2 μm deposited on either Corning 7059 or quartz substrates. For glass-deposited samples the absorption curves derived from each method diverge considerably for photon energies less than 1 eV and the PDS results exhibit a marked dependence on thickness. By depositing on quartz substrates, both PDS and CPM results are in close agreement at all energies and the thickness dependence in the PDS measurements disappears. These results are explained in terms of absorption in the 7059 glass substrate which can lead to serious overestimates of the film absorption data from PDS experiments.

ISSN:0950-0839    

DOI:10.1080/09500838908206336

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Hydrogenated amorphous silicon-carbon thin-films (a-SixCy: H) were prepared so as to obtain sets of films with different thicknesses for each of two differing growth conditions. Double Schottky barrier electrodes were used to study the space-charge-limited current (SCLC) through each film and the scaling law for this conduction mechanism was tested for each of the two preparative conditions. This scaling law was valid only if the deposition was uninterrupted during movement of a mask which was rotated so as to cover sequentially parts of the substrate. Films which were deposited in several layers, with brief interruptions for mask movement, appear to have additional states at each interface which dominate the bulk states being intentionally probed by the SCLC technique.

ISSN:0950-0839    

DOI:10.1080/09500838908206337

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor