Vacancy effect on the elastic constants of layer-structured nanomaterials

Karakasidis, TE; Charitidis, CA

dc.contributor.author	Karakasidis, TE	en
dc.contributor.author	Charitidis, CA	en
dc.date.accessioned	2014-03-01T01:32:23Z
dc.date.available	2014-03-01T01:32:23Z
dc.date.issued	2009	en
dc.identifier.issn	0167-8442	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/20106
dc.subject	Elastic constants	en
dc.subject	Grain boundaries	en
dc.subject	Mechanical properties	en
dc.subject	Molecular dynamics	en
dc.subject	Nanostructured materials	en
dc.subject	Vacancies	en
dc.subject.classification	Engineering, Mechanical	en
dc.subject.classification	Mechanics	en
dc.subject.other	Alternating layers	en
dc.subject.other	Atomistic simulations	en
dc.subject.other	Bulk value	en
dc.subject.other	Elastic properties	en
dc.subject.other	Experimental methods	en
dc.subject.other	External stress	en
dc.subject.other	Fabrication method	en
dc.subject.other	High angle grain boundaries	en
dc.subject.other	Homogeneous deformation	en
dc.subject.other	Layer width	en
dc.subject.other	Lennard-Jones potential	en
dc.subject.other	Model system	en
dc.subject.other	Multi-scale modelling	en
dc.subject.other	Nano-materials	en
dc.subject.other	System energy	en
dc.subject.other	Vacancy effects	en
dc.subject.other	Elasticity	en
dc.subject.other	Grain boundaries	en
dc.subject.other	Grain size and shape	en
dc.subject.other	Mechanical properties	en
dc.subject.other	Metal analysis	en
dc.subject.other	Molecular dynamics	en
dc.subject.other	Nanocrystallites	en
dc.subject.other	Nanostructured materials	en
dc.subject.other	Systems engineering	en
dc.subject.other	Vacancies	en
dc.subject.other	Vibrations (mechanical)	en
dc.subject.other	Elastic constants	en
dc.title	Vacancy effect on the elastic constants of layer-structured nanomaterials	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.tafmec.2009.05.007	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.tafmec.2009.05.007	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	Layer-structured nanomaterials where alternating layers of nanocrystallites meet along high angle grain boundaries constitute a special category of nanomaterials. In the present study we investigated the effect of the presence of a vacancy on the elastic constants of such materials by the use of atomistic simulation methods. The calculations were performed on a model system where atoms interact via a Lennard-Jones potential and the elastic constants were obtained in the frame of homogeneous deformations, for nano-crystallite layer widths ranging from 2.24 up to 37.12 nm. The results show that the favoured position of the vacancy is located in the GB core. The state of relaxation of the structure is an important factor that affects the obtained results. in both the unrelaxed and relaxed structures results converge to a given value after the 5th (3 10) layer. This value seems to depend on the size of the nanocrystallite L and approaches the bulk value above a given size L. It is also concluded that in the case of a relaxed system there is a smoother variation of the system energy and elastic constant as a function of the distance of the vacancy from the GB plane when the size L increases. The way that external stresses are applied on the system affects the values of the obtained elastic properties, with the elastic constants related to the characteristic directions of the grain boundary being the most affected ones. These findings are of particular interest for fabrication methods of nanostructured materials, experimental methods for the measurement of their elastic properties as well as multiscale modelling schemes. (C) 2009 Elsevier Ltd. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Theoretical and Applied Fracture Mechanics	en
dc.identifier.doi	10.1016/j.tafmec.2009.05.007	en
dc.identifier.isi	ISI:000268384200007	en
dc.identifier.volume	51	en
dc.identifier.issue	3	en
dc.identifier.spage	195	en
dc.identifier.epage	201	en