Volume 109, Number 5, March 2015
|Number of page(s)||6|
|Section||Condensed Matter: Structural, Mechanical and Thermal Properties|
|Published online||16 March 2015|
Adsorption-induced strain of a nanoscale silicon honeycomb
1 Institut des NanoSciences de Paris, CNRS, UPMC Univ. Paris 6 - 4, place Jussieu, 75005 Paris, France
2 Interfaces, Confinement, Matériaux et Nanostructures, CNRS UMR7374, Université d'Orléans 1b rue de la Férollerie, 45071 Orléans cedex 02, France
3 Laboratoire de Physique Statistique de l'ENS, associé au CNRS et aux Universités Paris 6 et Paris 7 24 rue Lhomond, 75005 Paris, France
Received: 5 December 2014
Accepted: 25 February 2015
We report on systematic measurements of both adsorption and anisotropic mechanical deformations of mesoporous silicon, using heptane at room temperature. Porous Si obtained from highly doped (100) Si can be thought of as a nanoscale random honeycomb with pores parallel to the  axis. We show that strains and measured along and transversely to the pore axis exhibit a hysteretic behavior as a function of the fluid pressure, which is due to the hysteresis in fluid adsorption. The pressure dependence of the strains together with the independent measurement of the transverse stress, allows us to determine the biaxial transverse modulus and to estimate the longitudinal Young's modulus of porous Si. We argue that the value of these constants implies that Young's modulus of the 6 nm thick walls of the honeycomb is about 5 times smaller than that of bulk silicon, striking evidence of finite-size effects.
PACS: 68.43.-h – Chemisorption/physisorption: adsorbates on surfaces / 62.20.de – Elastic moduli
© EPLA, 2015
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.