摘要:

In situexperiments are performed in Ni3AL at room temperature. We observe reversible changes of antiphase boundary (APB) planes between {111} and {100}, and movements in {111} planes controlled by the crossing of sessile positions with the APB plane in {111}.

ISSN:0950-0839    

DOI:10.1080/09500838808214763

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A master equation for grain growth is suggested for the one-particle distribution of grain areas and topological classes in two-dimensional polycrystals with uniform properties of grain boundaries. The ‘collision’ term for a self-similar mode (normal grain growth) is formulated within the ‘gas’ approximation, assuming equal probabilities of neighbour switchings for all the grain boundaries and ignoring mutual arrangement of grains.

ISSN:0950-0839    

DOI:10.1080/09500838808214764

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The one-particle distribution of grains in topological classes and normalized areas is obtained from a computer simulation based on the master equation of normal grain growth in two dimensions. The ‘collision’ term is formulated in the ‘gas’ approximation. Comparison with physical experiment is provided.

ISSN:0950-0839    

DOI:10.1080/09500838808214765

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Very fine transformation twins with a thickness of 1-5 nm have been found in a b.c.t. martensite having an abnormally high tetragonality. The (112) boundaries of these ultrafine twins are fragmented and have many steps with a height of 1–6 interplanar distances of the (112) planes, which seems to be a result of the accommodation of local strains at the austenite-martensite interface on an atomic scale.

ISSN:0950-0839    

DOI:10.1080/09500838808214766

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Streaking in electron diffraction patterns from aluminium samples containing inert-gas bubbles has recently been used as evidence for the presence of three quite different microstructural features. Detailed investigations into the origins of the streaking indicate that an additional mechanism, not considered in the previous work, may be the primary cause of streaking in all of the cases considered.

ISSN:0950-0839    

DOI:10.1080/09500838808214767

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Amorphous thin 6lms of Ge20Bi4Se76exhibiting n-type conduction are reported for the first time. As compared to a-Ge20Se80films, the modified films (a-Ge20Bi4Se76) show an increase in room-temperature electrical conductivity by several orders of magnitude, a transition from p-to n-type conduction, a decrease in the optical gap from 1.9 to 1.5 eV and a drastic fall in the electrical activation energy from 0.85 to 0.17eV. The correlation of the electrical and optical data suggests the existence of localized states at the conduction band edge arising from the incorporation of bismuth. The decrease of the activation energy for electrical conduction is much larger than the decrease of one-half the optical gap. This indicates unpinning of the Fermi level with a shift towards the conduction band edge.

ISSN:0950-0839    

DOI:10.1080/09500838808214768

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor