Magnon specific heat and magnetic susceptibility of Fe/Gasb diluted magnetic semiconductor in the presence of applied electric field, magnetic field, and anisotropic energy
Ferromagnetism has been established in a Fe-doped ferromagnetic semiconductor Fe/GaSb with the Curie-Weiss temperature of 340 K for dopant concentration, x = 25%. These ferromagnetic semiconductors are very promising candidates for future spintronic devices as they show both semiconducting and magnetic properties. Ferromagnetism can be tuned and controlled by application of electric and magnetic fields, and by radiation. In the present work, the importance of dopant concentration x, effects of electric and magnetic fields, and magnetic anisotropy on the magnon specific heat and magnetic susceptibility of Fe/GaSb are studied. Heisenberg localized spin model Hamiltonian with account of nearest neighbor interaction and with the electric and magnetic fields applied, and magnetic anisotropy energy included is second quantized using Holstien-Primakoff transformation to obtain the magnon dispersion from which magnon specific heat and magnetic susceptibility are calculated. Our results show that the magnon specific heat decreases with the increase of magnetic impurity concentration x, while magnetic susceptibility increases. It is also shown that electric and magnetic fields, and magnetic anisotropy can control the magnetic properties of the diluted magnetic semiconductors which are of vital importance for spintronics applications. The results obtained are in broad agreement with experimental and theoretical predictions.