THE STUDY OF THERMAL PROPERTIES IN DILUTED MAGNETIC SEMICONDUCTOR 𝑮𝒂𝑴𝒏𝑨s

Abstract A semiconductor is a material that is an insulator at very low temperature, but which has a suitable electrical conductivity at room temperature. It is also described as an insulator with a band gap small enough that its conduction band is appreciably thermally populated at room temperature. An intrinsic semiconductor is one which is pure enough that impurities do not appreciably affect its electrical behavior. An extrinsic semiconductor is one that has been doped with impurities to modify the number and type of free charge carriers. The thermal properties of III - V diluted magnetic semiconductor, GaMnAs is studied. The Hamiltonian of the system is determined by both Heisenberg and Green’s formulations. Here the attention is given to the theoretical understanding of the thermal behavior of GaMnAs. Using the Greens formalism the thermal properties such as heat capacity and specific heat capacities are calculated for both ferromagnetic and antiferromagnetic states. For the magnetic ion (𝑀𝑛2+ ) concentration x = 0.4, the specific heat capacity is determined. The calculated results indicate that the specific heat capacity of GaMnAs is proportional to 𝑇 3/2 for ferromagnetic phase. On the other hand, the specific heat capacity of the GaMnAs is directly proportional to the cube of temperature for antiferromagnetic state.