Browsing by Author "Paul, Roni"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Evaluation of Co80Pt20 Films for Power Inductor Applications(University of Alabama Libraries, 2021) Paul, Roni; Kotru, Sushma; University of Alabama TuscaloosaMagnetic components such as inductors and transformers are the largest components for power conversion circuits. There is a consistent effort to reduce the size of these components. Thin film technology is introduced to downsize these components, and ferrite films are used to build inductors. However, the core gets saturated at a very low current. Using a permanent magnet between the ferrite films can increase the saturation current by almost double. In this work, CoPt thin films were evaluated as a potential candidate material as a permanent magnet for such applications. CoPt films were deposited at room temperature using a magnetron sputtering system. CoPt films with four different thickness were deposited. The films were annealed in vacuum in the sputtering chamber at 700 ℃ for 30 minutes. XRD was done for phase identification. The thickness of these films was measured using a scanning electron microscope (SEM), and compositional analysis was done by Energy Dispersive Spectroscopy (EDS). The magnetitic studies on these films were performed using Alternating Gradient Magnetometer (AGM) and Vibrating Sample Magnetometer (VSM).Item Evaluation of Magnetic Films for Inductor and Optoelectronic Applications(University of Alabama Libraries, 2023) Paul, Roni; Kotru, Sushma SMagnetic films find applications in various technologies, such as high-density magnetic recording, magnetic random-access memories, micromechanical devices, miniature magnetic sensing devices, transformers, and inductors. In the case of ferrite core inductors, soft magnetic ferrite films are utilized as the magnetic core due to their desirable properties like high resistivity, permeability, and saturation magnetization. However, these cores tend to saturate with low currents, which limits the saturation current of the power inductor. To overcome this limitation, the development of new structures is proposed, which involve the use of hard magnetic films with high saturation magnetization and coercivity. The objective of this study is to assess the potential use of nickel-zinc ferrite films as soft magnetic materials and cobalt platinum films as hard magnetic materials in the fabrication of an inductor. Additionally, the nickel-zinc ferrite films are evaluated for their suitability in optoelectronic applications due to their favorable optical properties. Pure nickel-zinc ferrite (NZF), Cu-doped nickel-zinc ferrite (NCuZF), and Co-doped nickel-zinc ferrite (NCoZF) films were prepared using the sol-gel method and characterized for their structural, optical, and magnetic properties. The results indicate that the magnetic and optical properties of these films can be tuned by doping the films. Doping with Cu improved the properties making NCuZF films suitable for inductor applications, whereas doping the films with Co improved the optical properties making NCoZF films suitable for optoelectronic applications. For inductor applications, thicker films are required. So, thick films of NCuZF films were prepared using a combination of sputtering and sol-gel methods and evaluated for magnetic properties. Further thick films of Cobalt Platinum were deposited using DC sputtering. The dissertation presents the results of the optimization process of thin and thick film preparation of ferrite and CoPt films along with their structural, magnetic, and optical characterization. Characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), alternating gradient magnetometry (AGM), and vibrating sample magnetometry (VSM) which were used for this study are described. Finally, the fabrication of air core and ferrite core inductors using film fabrication, photolithography, and lift-off processes are also presented.