Science and Education Publishing
International Journal of Physics
2
1
2014
01
17
Anharmonicity and Disorder Effect on the Free Energy of Crystalline Solids
1
7
EN
M. Ataullah
Ansari
B.D.
Indu
Physics Department, Indian Institute of Technology, Roorkee, Uttarkahand, India
IJP2014211
10.12691/ijp-2-1-1
2013
12
20
2014
01
07
2014
01
17
Dealing with the anharmonic phonon-electron problem with the help of double time temperature dependent Green's Function theory of quantum dynamics the general and explicit expressions for the lattice energy, partition function, free energy have been derived for an impurity induced anharmonic crystalline solid. The effects of mass and force constant change terms between the impurity and host lattice atoms are taken into account, and the cubic and quartic anharmonic terms are also retained in an almost complete Hamiltonian to develop the many body theory. The general trend of low and high temperature contributions to Helmholtz free energy is obtained via three dimensional graphics.