Pressure Dependence of Frequencies and Frequencies Distribution Function for Aluminum: Theoretical approach

A theoretical study was made of the pressure dependence of lattice frequencies and distribution function for aluminum by analyzing phonon frequency spectrum, using Grneisen approximation and many equations of state (EOS). Each change in the specific volume of a crystal excites a change in the frequencies of lattice vibration in a very complex manner . This work shows how this complexity can be overcome at least approximately depe- nding on Grneisen approximation and Murnaghan , Birch- Murnaghan and Vinet equations of state.