Showing papers by "Qunyang Li published in 2006"
TL;DR: In this paper, a diamagnetic lateral force calibrator (D-LFC) was developed to directly calibrate atomic force microscope (AFM) cantilever-tip or bead assemblies.
Abstract: A novel diamagnetic lateral force calibrator (D-LFC) has been developed to directly calibrate atomic force microscope (AFM) cantilever-tip or -bead assemblies. This enables an AFM to accurately measure the lateral forces encountered in friction or biomechanical-testing experiments at a small length scale. In the process of development, deformation characteristics of the AFM cantilever assemblies under frictional loading have been analyzed and four essential response variables, i.e., force constants, of the assembly have been identified. Calibration of the lateral force constant and the “crosstalk” lateral force constant, among the four, provides the capability of measuring absolute AFM lateral forces. The D-LFC is composed of four NdFeB magnets and a diamagnetic pyrolytic graphite sheet, which can calibrate the two constants with an accuracy on the order of 0.1%. Preparation of the D-LFC and the data processing required to get the force constants is significantly simpler than any other calibration methods...
177 citations
TL;DR: In this paper, the surface stability and morphology evolution of a soft elastic film subjected to surface interactions such as van der Waals forces are investigated in terms of the surface energy, film thickness and elastic constants.
46 citations
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TL;DR: In this article, the exchange bias of the magnetic hysteresis as a function of both core radius and shell thickness, at low temperature, was investigated by using Monte Carlo simulation on a ferromagnetic core/antiferromagnetic shell nanoparticle.
Abstract: By using Monte Carlo simulation on a ferromagnetic core/antiferromagnetic shell nanoparticle, we investigate in details the exchange bias of the magnetic hysteresis as a function of both core radius and shell thickness, at low temperature. It is found that the exchange bias is very sensitive to the core radius and a small variation of the radius may lead to a big fluctuation of the bias. In a general tendency the exchange bias is enhanced by increasing shell thickness and decreasing core radius. The intrinsic correlation between the exchange bias and the spin configuration on the core-shell interface is demonstrated. We further investigate the dependence of the exchange bias on temperature and random field inside the nanoparticle, indicating a monotonous decreasing of the bias with the magnitude of random field and temperature, respectively.
1 citations