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Ab initio study of surface stresses of charged Au films

: Umeno, Y.; Weissmueller, J.; Elsaesser, C.; Meyer, B.; Gumbsch, P.

Materials Research Society -MRS-:
Mechanics of nanoscale materials and devices : April 17 - 21, 2006, San Francisco, California, USA
Warrendale, Pa.: MRS, 2006 (Materials Research Society Symposium Proceedings 924)
ISBN: 1-558-99881-0
ISBN: 978-1-558-99881-0
ISSN: 0272-9172
Symposium "Mechanics of Nanoscale Materials and Devices" <2006, San Francisco/Calif.>
Materials Research Society (Spring Meeting) <2006, San Francisco/Calif.>
Conference Paper
Fraunhofer IWM ()

It has been observed in experiments that charging of nanometer-sized porous material can lead to expansion or contraction of this material. This effect can be explained by a change in surface stress as a function of surface electron charge density. Here, we employ ab initio density functional calculations using a mixed-basis pseudopotential approach to study the change in surface stresses, f, as a function of surface charge density, q for Au thin films with (111) and (100) surfaces. The derivative of the surface stress with respect to the charge, f/q, at equilibrium is related to and can be evaluated from /e of an uncharged slab, where is the chemical potential of the electrons in the slab and e the tangential strain. The responses of the (111) and (100) surfaces to charging are evaluated in this way as -1.86 V and -0.90 V, respectively. The calculated values compare well to experimental observations (-0.9 V).