The Core Structure and the Mobility of Dislocations in Ice
Abstract The evidence concerning the velocity of glide of dislocations on the (0001) plane of ice Ih is reviewed and related to atomic processes occurring within or near the dislocation core. The velocity is directly proportional to stress at low stress, with a value of the order of 500 Burgers vect...
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Cambridge University Press (CUP)
1978
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Online Access: | http://dx.doi.org/10.1017/s0022143000033529 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000033529 |
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crcambridgeupr:10.1017/s0022143000033529 2024-03-03T08:45:59+00:00 The Core Structure and the Mobility of Dislocations in Ice Whitworth, R. W. 1978 http://dx.doi.org/10.1017/s0022143000033529 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000033529 en eng Cambridge University Press (CUP) Journal of Glaciology volume 21, issue 85, page 341-359 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1978 crcambridgeupr https://doi.org/10.1017/s0022143000033529 2024-02-08T08:32:56Z Abstract The evidence concerning the velocity of glide of dislocations on the (0001) plane of ice Ih is reviewed and related to atomic processes occurring within or near the dislocation core. The velocity is directly proportional to stress at low stress, with a value of the order of 500 Burgers vectors per second at — 18 ° C and a stress of 10 5 N m -2 . The usual idea of a dislocation core is that it is “crystalline” in the sense that the linkages between molecules are as far as possible the same as those in the normal lattice. For such a model the disorder of protons presents an obstacle to dislocation movement, and recent theories predict that dislocations should not be able to glide as fast as they are observed to do. Various ways of avoiding this difficulty within the context of a crystalline core are discussed, but none seems likely to be successful. An alternative model is that the core is “non-crystalline”, with a disordered arrangement of mobile molecules within it. The movement of such dislocations should not be seriously impeded by proton disorder. Dislocation mobility would then be limited at least in part by anelastic loss due to the stress-induced order of protons in the surrounding lattice. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 21 85 341 359 |
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Open Polar |
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Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Whitworth, R. W. The Core Structure and the Mobility of Dislocations in Ice |
topic_facet |
Earth-Surface Processes |
description |
Abstract The evidence concerning the velocity of glide of dislocations on the (0001) plane of ice Ih is reviewed and related to atomic processes occurring within or near the dislocation core. The velocity is directly proportional to stress at low stress, with a value of the order of 500 Burgers vectors per second at — 18 ° C and a stress of 10 5 N m -2 . The usual idea of a dislocation core is that it is “crystalline” in the sense that the linkages between molecules are as far as possible the same as those in the normal lattice. For such a model the disorder of protons presents an obstacle to dislocation movement, and recent theories predict that dislocations should not be able to glide as fast as they are observed to do. Various ways of avoiding this difficulty within the context of a crystalline core are discussed, but none seems likely to be successful. An alternative model is that the core is “non-crystalline”, with a disordered arrangement of mobile molecules within it. The movement of such dislocations should not be seriously impeded by proton disorder. Dislocation mobility would then be limited at least in part by anelastic loss due to the stress-induced order of protons in the surrounding lattice. |
format |
Article in Journal/Newspaper |
author |
Whitworth, R. W. |
author_facet |
Whitworth, R. W. |
author_sort |
Whitworth, R. W. |
title |
The Core Structure and the Mobility of Dislocations in Ice |
title_short |
The Core Structure and the Mobility of Dislocations in Ice |
title_full |
The Core Structure and the Mobility of Dislocations in Ice |
title_fullStr |
The Core Structure and the Mobility of Dislocations in Ice |
title_full_unstemmed |
The Core Structure and the Mobility of Dislocations in Ice |
title_sort |
core structure and the mobility of dislocations in ice |
publisher |
Cambridge University Press (CUP) |
publishDate |
1978 |
url |
http://dx.doi.org/10.1017/s0022143000033529 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000033529 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 21, issue 85, page 341-359 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000033529 |
container_title |
Journal of Glaciology |
container_volume |
21 |
container_issue |
85 |
container_start_page |
341 |
op_container_end_page |
359 |
_version_ |
1792501731880337408 |