TY - JOUR
T1 - Vibrational Properties of Vacancy in Na and K Using MEAM Potential
AU - Vandana Gairola & P. D. Semalty
JO - Communications in Computational Physics
VL - 2
SP - 556
EP - 568
PY - 2014
DA - 2014/02
SN - 15
DO - http://doi.org/10.4208/cicp.090113.070813a
UR - https://global-sci.org/intro/article_detail/cicp/7105.html
KW - 
AB - <p style="text-align: justify;">The modified embedded atom method (MEAM) with the universal form of
embedding function and a modified energy term along with the pair potential has
been employed to determine the potentials for alkali metals: Na, K, by fitting to the
Cauchy pressure (<em>C</em><sub>12</sub>−<em>C</em><sub>44</sub>)/2, shear constants <em>G</em><sub>v</sub> = (<em>C</em><sub>11</sub>−<em>C</em><sub>12</sub>+3<em>C</em><sub>44</sub>)/5 and <em>C</em><sub>44</sub>, the
cohesive energy and the vacancy formation energy. The obtained potentials are used
to calculate the phonon dispersions of these metals. Using these calculated phonons
we evaluate the local density of states of neighbours of vacancy using Green&#39;s function
method. The local density of states of neighbours of vacancy has been used to calculate
mean square displacements of these atoms and formation entropy of vacancy. The
calculated mean square displacements of both 1st and 2nd neighbours of vacancy are
found to be lower than that of host atom. The calculated phonon dispersions agree well
with the experimental phonon dispersion curves and the calculated results of vacancy
formation entropy compare well with the other available results.</p>