Landau-de Gennes model with the inclusion of density change for the nematic-isotropic phase transition

The Landau-de Gennes model of the nematic-isotropic phase transition with the inclusion of the density change and a higher order term (sixth-order term) in a simple way is examined. The temperature difference T-NI - T* obtained is in good agreement with the experimental one. We also obtained the value of the ratio (Q* - Q(NI))/Q(NI) The value of (Q* - Q(NI))/Q(NI) is not improved over the earlier attempt, but there is a definite improvement in the value of T-NI - T* which is obtained as 1.045 K.