<b>Nanocomposite Designs for Tunable Magnetic Properties</b>

<p dir="ltr">Magnetic materials are used throughout our daily lives due to how necessary they are for the functioning of electronic devices. As the demand for smaller, more advanced devices grows, the need for multifunctional devices becomes even more emerging. Vertically aligned nanocomposites (VANs) offer a unique solution, enabled by a one-step deposition process of two materials, one forming pillars and the other serving as the matrix. This unique microstructure integrates both materials’ properties and allows for interactions between the pillars and the matrix, providing new opportunities for enhanced and/or coupled performance.</p><p dir="ltr">In this dissertation, four different studies of different magnetic materials were performed to understand how VAN can better tuning their properties. First, the target composition study established a new method for developing VAN microstructures for complex oxide-oxide systems by adjusting the target configuration used during deposition. The deposited films showed tunable magnetic and optical properties. Second, the CoFeB-BiFeO₃ study showed the demonstration of a new multiferroic material with antiferromagnetic-ferromagnetic exchange coupling stronger than that of a CoFeB-BiFeO₃ bilayer film. Third, CeO₂-NiFe VANs demonstrated how shape anisotropy improves NiFe’s magnetic properties without sacrificing its magnetic permeability. This work also established the first demonstration of ferromagnetic resonance in a VAN film. Fourth, the YIG-Au project developed a method to couple optical anisotropy with YIG’s magnetic properties, allowing for optically controlled spintronic devices. Some of the YIG-Au VAN films even demonstrated a lower magnetic damping than that of a pure YIG film. Overall, these findings pave a way for next-generation device applications with magnetic nanocomposites.</p><p><br></p>