Universal binding energy relation for cleaved and structurally relaxed surfaces

Srirangarajan, Aarti and Datta, Aditi and Gandi, Appala Naidu and Ramamurty, U and Waghmare, UV (2014) Universal binding energy relation for cleaved and structurally relaxed surfaces. In: JOURNAL OF PHYSICS-CONDENSED MATTER, 26 (5).

PDF jou_phy_con_mat_26-5_2014.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

The universal binding energy relation (UBER), derived earlier to describe the cohesion between two rigid atomic planes, does not accurately capture the cohesive properties when the cleaved surfaces are allowed to relax. We suggest a modified functional form of UBER that is analytical and at the same time accurately models the properties of surfaces relaxed during cleavage. We demonstrate the generality as well as the validity of this modified UBER through first-principles density functional theory calculations of cleavage in a number of crystal systems. Our results show that the total energies of all the relaxed surfaces lie on a single (universal) energy surface, that is given by the proposed functional form which contains an additional length-scale associated with structural relaxation. This functional form could be used in modelling the cohesive zones in crack growth simulation studies. We find that the cohesive law (stress-displacement relation) differs significantly in the case where cracked surfaces are allowed to relax, with lower peak stresses occurring at higher displacements.

Item Type:	Journal Article
Publication:	JOURNAL OF PHYSICS-CONDENSED MATTER
Publisher:	IOP PUBLISHING LTD
Keywords:	density functional theory (DFT); fracture; surface energy; total energy calculations; universal binding energy relation (UBER)
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	06 Mar 2014 06:51
Last Modified:	06 Mar 2014 06:51
URI:	http://eprints.iisc.ac.in/id/eprint/48492

Actions (login required)

View Item