5,084 research outputs found
Orientation and Motion of Water Molecules at Air/Water Interface
Analysis of SFG vibrational spectra of OH stretching bands in four
experimental configurations shows that orientational motion of water molecule
at air/water interface is libratory within a limited angular range. This
picture is significantly different from the previous conclusion that the
interfacial water molecule orientation varies over a broad range within the
vibrational relaxation time, the only direct experimental evidence for
ultrafast and broad orientational motion of a liquid interface by Wei et al.
[Phys. Rev. Lett. 86, 4799, (2001)] using single SFG experimental
configuration
Molecular dynamic simulation of low-energy FIB irradiation induced damage in diamond
In this article, a large scale multi-particle molecular dynamics (MD) simulation model was developed to study the dynamic structural changes in single crystal diamond under 5 keV Ga+ irradiation in conjunction with a transmission electron microscopy (TEM) experiment. The results show that the thickness of ion-induced damaged layer (∼9.0 nm) obtained from experiments and simulations has good accordance, which demonstrates the high accuracy achieved by the developed MD model. Using this model, the evolution of atomic defects, the spatial distributions of implanted Ga particles and the thermal spike at the very core collision area were analysed. The local thermal recrystallizations observed during each single ion collision process and the increase of the density of the non-diamond phase (mostly sp2 bonded) at irradiation area are fund to be the underling mechanisms responsible for ion fluence dependent amorphization of diamond observed in previous experiments
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