Balaji, S and Abinandanan, TA and Ayappa, KG and Chandrasekhar, N (2000) Molecular dynamics study of vacancy diffusion in a forced Lennard-Jones system. In: Philosophical Magazine A, 80 (2). pp. 301-310.Full text not available from this repository.
Using constant-temperature molecular dynamics simulations, we have investigated the effect of an alternating uniaxial external stress on vacancy migration in a fcc argon crystal in which the atoms interact with each other through a 12-6 Lennard-Jones potential. The crystal is confined between two smooth walls which interact with the atoms through a similar Lennard-Jones potential, and an alternating stress field is exerted by moving both the walls inwards (compressive) and outwards (expansive) sinusoidally with a frequency of 93 MHz. In the other two directions periodic boundary conditions are used. The amplitude of the sinusoidal wall movement along the  axis corresponds to a strain of 0.0138 and a stress of about 15 MPa. At this small strain amplitude, the vacancy jump frequency, when averaged over a full stress cycle, has a value similar to that in the bulk unstressed crystal. However, the vacancy jump frequency is higher with a larger proportion of jumps being in planes normal to the stress axis, during the expansive half-cycle than during the compressive half cycle. Thus, the jump behaviour is anisotropic under stress, and this anisotropy is opposite for the two half-cycles.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Taylor and Francis Group.|
|Department/Centre:||Division of Physical & Mathematical Sciences > Physics|
|Date Deposited:||11 Aug 2006|
|Last Modified:||22 Feb 2012 08:27|
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