SPECIFIC HEAT ESTIMATION FOR FERROMAGNETS WITHIN THE FRAMEWORK OF THE ISING MODEL

Abstract

This project presents the specific heat estimation for ferromagnetic material using the Ising model within the framework of the mean field approximation. First, a calculation is performed to obtain expression for partition function and for distribution function of magnetic moments of spin. The temperature dependence of Ising model is calculated using the Taylor expansion at below and above Curie temperature. Calculation shows that ferromagnetic materials have zero magnetization if temperature is kept above the Curie temperature (Tc). But when temperature drops and approaches the Tc, these systems displays sudden magnetization whose magnitude increases and saturates as temperature decreases below Tc . Specific heat of the Ising model near Curie temperature of the system is calculated in this work using transfer matrix function. As temperature approaches to Curie temperature, specfic heat diverges logarithmically to infinity, but at the critical temperature, T = Tc it reaches its maximum value and found to be very sharp peaked. Finally, internal and free energy of phase transition system also has been calculated, and the free energy is decreasing with the increase of temperature