Abstract:
This thesis investigates the effects of temperature, magnetic impurity concentration, and
photon irradiation on the ferromagnetic properties of manganese-doped GaAs diluted magnetic
semiconductors. By employing the equation of motion approach within the Green
function formalism, we derived theoretical expressions for magnon energy dispersion, magnon
density, system magnetization, and magnon heat capacity. Our findings reveal that magnon
dispersion energy increases quadratically with wave vector but is suppressed with higher
impurity concentrations, indicating altered spin interactions in the material. Temperature
elevation enhances magnon density due to increased thermal disruption of magnetic ordering,
while photon irradiation further amplifies magnon density through spin scattering. Moreover,
increased magnetic impurity concentration enhances the system’s magnetization by
introducing additional magnetic spins that promote magnetic ordering, although excessive
impurity levels may introduce competing effects such as antiferromagnetic interactions. Conversely,
magnetization decreases with rising temperatures and photon coupling strength
due to competing thermal and photon energies. These results highlight the critical roles of
doping, temperature control, and photon management in optimizing the magnetic properties
of diluted magnetic semiconductors, with significant implications for the advancement of
spintronic devices, magnetic sensors, and data storage technologies. This research contributes
to a deeper understanding of the dynamic interplay between external factors and the intrinsic
magnetic properties of semiconductor materials, providing a foundation for future
technological advancements.
