David Holec, Martin Friák, AntonĂ­n Dlouhý, Jörg Neugebauer. Ab initio study of pressure stabilised NiTi allotropes: pressure-induced transformations and hysteresis loops


Natural Sciences / Physics / Condensed Matter Physics

Submitted on: Aug 22, 2012, 05:03:44

Description: Changes in stoichiometric NiTi allotropes induced by hydrostatic pressure have been studied employing density functional theory. By modelling the pressure-induced transitions in a way that imitates quasi-static pressure changes, we show that the experimentally observed B19' phase is (in its bulk form) unstable with respect to another monoclinic phase, B19". The lower symmetry of the B19" phase leads to unique atomic trajectories of Ti and Ni atoms (that do not share a single crystallographic plane) during the pressure-induced phase transition. This uniqueness of atomic trajectories is considered a necessary condition for the shape memory ability. The forward and reverse pressure-induced transition B19'{$leftrightarrow$}B19" exhibits a hysteresis that is shown to originate from hitherto unexpected complexity of the Born-Oppenheimer energy surface.

The abstract of this article will be published in the August 2012 issue of "Intellectual Archive Bulletin", ISSN 1929-1329.

The Library and Archives Canada reference page: collectionscanada.gc.ca/ourl/res.php?url_ver=Z39.88......

To read the article posted on Intellectual Archive web site please click the link below.

David_Holec__Ab_initio_study_of_pressure.pdf



© 2011-2017 Shiny World Corp. All rights reserved. To reach us please send an e-mail to support@IntellectualArchive.com