Physisorption may cause a dimple on a deformable solid surface due to adsorbat-substrate interaction. The interactive force between the adsorbate and the crystal atoms depends on their distances, which may change with...Physisorption may cause a dimple on a deformable solid surface due to adsorbat-substrate interaction. The interactive force between the adsorbate and the crystal atoms depends on their distances, which may change with substrate deformation. This feature of displacement-dependence indicates that the equilibrium problem is a force-deformation coupled nonlinear procedure. In the present study, a continuum mechanics model, in which the force is considered as a function of the displacement field of the medium, is presented to calculate the physisorption-induced deformation in a semi-infinite elastic medium. It is found that the nonlinear effect due to force-deformation coupling should be taken in consideration in the adsorbate-substrate interaction analysis.展开更多
The autonomy and property of atoms/molecules adsorbed on the surface of a microcantilever can be probed by measuring its resonance frequency shift due to adsorption.The resonance frequency change of a cantilever induc...The autonomy and property of atoms/molecules adsorbed on the surface of a microcantilever can be probed by measuring its resonance frequency shift due to adsorption.The resonance frequency change of a cantilever induced by chemisorption is theoretically studied. Oxygen chemisorbed on the Si(100) surface is taken as a representative example.We demonstrate that the resonant response of the cantilever is mainly determined by the chemisorption-induced bending stiffness variation,which depends on the bond configurations formed by the adsorbed atoms and substrate atoms.This study is helpful for optimal design of microcantilever-based sensors for various applications.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 10572067, 10525210 and 10121202, and the National Basic Research Programme of China under Grant No 2007CB936803.
文摘Physisorption may cause a dimple on a deformable solid surface due to adsorbat-substrate interaction. The interactive force between the adsorbate and the crystal atoms depends on their distances, which may change with substrate deformation. This feature of displacement-dependence indicates that the equilibrium problem is a force-deformation coupled nonlinear procedure. In the present study, a continuum mechanics model, in which the force is considered as a function of the displacement field of the medium, is presented to calculate the physisorption-induced deformation in a semi-infinite elastic medium. It is found that the nonlinear effect due to force-deformation coupling should be taken in consideration in the adsorbate-substrate interaction analysis.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11102043,10732050 and 11072170the National Basic Research Program of China under Grant No 2010CB631005the Doctorial Start-up Fund of Guangdong University of Technology under Grant No 083065.
文摘The autonomy and property of atoms/molecules adsorbed on the surface of a microcantilever can be probed by measuring its resonance frequency shift due to adsorption.The resonance frequency change of a cantilever induced by chemisorption is theoretically studied. Oxygen chemisorbed on the Si(100) surface is taken as a representative example.We demonstrate that the resonant response of the cantilever is mainly determined by the chemisorption-induced bending stiffness variation,which depends on the bond configurations formed by the adsorbed atoms and substrate atoms.This study is helpful for optimal design of microcantilever-based sensors for various applications.
