High pressure equation of state for nano materials

Abstract

In the present paper, the modified Shanker formulation by Kumar and Kumar, Indian J Pure & Appl Phys, 46 (2008) 378) to study the compression behaviour of carbon nanotubes (bundle and individual tube) has been shown to be mathematically inconsistent. It is mentioned that one should modify the Suzuki EOS rather than the Shanker EOS, as Suzuki EOS is also not mathematically consistent while the Shanker EOS is thermodynamically and mathematically consistent. The results obtained using the thermodynamically consistent formulation (modified Suzuki EOS) are found to be in better agreement with the experimental data than the Shanker and Suzuki EOS for compression behaviour. Pressure dependence of bulk modulus and its first order pressure derivative for carbon nanotubes using the present formulation are also given and discussed.