Graduation Year
2023
Document Type
Dissertation
Degree
Ph.D.
Degree Name
Doctor of Philosophy (Ph.D.)
Degree Granting Department
Physics
Major Professor
Dario A. Arena, Ph.D.
Committee Member
Ghanim Ullah, Ph.D.
Committee Member
Dmitry Voronin, Ph.D.
Committee Member
Nasir Ghani, Ph.D.
Keywords
Ferrimagnet, Ferromagnet, Ferromagnetic Resonance, Magnetism, Thin Film
Abstract
Spintronics traditionally relied on ferromagnetic materials for their strong spin properties but facedissues like large stray magnetic fields. To address these challenges, researchers turned to antiferromagnetic materials with fast spin dynamics, due to their zero net magnetic moment but the lack of a net spin moment complicated operation. In this context, ferrimagnetic materials have emerged as promising alternatives. They combine ferromagnetic and antiferromagnetic traits and feature different magnetic ions in their sublattices. This dissertation explores how film thickness and capping materials affect the properties of ferrimagnetic thin films. Rare-earth transition metal ferrimagnetic amorphous alloys have garnered attention in the realm of spintronics applications. These alloys provide the means to fine-tune magnetic attributes such as magnetization, anisotropy, and spin polarization by manipulating factors like composition, film thickness, temperature, and the selection of capping materials. Additionally, they exhibit a phenomenon called magnetic compensation, in which the temperature-dependent magnetization behaviors of the transition metals (Fe & Co) and rare earth (Gd) constituents nearly offset each other. This dissertation focuses on investigating how the magnetic properties of these materials evolve when altering the capping materials and adjusting the concentration of Gd within the thin films. This study delves into the magnetic characteristics of FeCoGd ferrimagnetic thin films by employing magnetometry, magneto-optical Kerr effect (MOKE), and ferromagnetic resonance (FMR) techniques. Another class of materials, exemplified by Heusler compounds such as Co2MnGa, has attracted significant attention. These compounds are renowned for their Weyl fermion lines and topological surface states, and they have garnered interest due to their negative magnetoresistance, high spin polarization, and low magnetic damping. We explored the influence of thickness and temperature on ferromagnetic resonance (FMR) film with the magnetic field aligned along the [110] and [100] directions. Our investigation unveiled a distinctive double peak pattern in the FMR response.
Scholar Commons Citation
Alzahrani, Noha, "Influence of Thickness and Capping Materials on the Static and Dynamic Properties of Ferrimagnetic Thin Films" (2023). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/10021
