2,594 research outputs found
An atomistic investigation of the effect of strain on frictional properties of suspended graphene
We performed molecular dynamics (MD) simulations of a diamond probe scanned on a suspended graphene to reveal the effect of strain on the fictional properties of suspended graphene. The graphene was subjected to some certain strain along the scanning direction. We compared the friction coefficient obtained from different normal loads and strain. The results show that the friction coefficient can be decreased about one order of magnitude with the increase of the strain. And that can be a result of the decreased asymmetry of the contact region which is caused by strain. The synthetic effect of potential energy and the fluctuation of contact region were found to be
the main reason accounting for the fluctuation of the friction force. The strain can reduce the fluctuation of the contact region and improve the stability of friction
Insight into perovskite antiferroelectric phases: Landau theory and phase field study
Understanding the appearance of commensurate and incommensurate modulations
in perovskite antiferroelectrics (AFEs) is of great importance for material
design and engineering. The dielectric and elastic properties of the AFE domain
boundaries are lack of investigation. In this work, a novel Landau theory is
proposed to understand the transformation of AFE commensurate and
incommensurate phases, by considering the coupling between the oxygen
octahedral tilt mode and the polar mode. The derived relationship between the
modulation periodicity and temperature is in good agreement with the
experimental results. Using the phase field study, we show that the
polarization is suppressed at the AFE domain boundaries, contributing to a
remnant polarization and local elastic stress field in AFE incommensurate
phases
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