Research Projects

This proposal aims to investigate key spintronic and magnonic phenomena in complex magnetic oxide systems composed of ferromagnetic insulators such as YIG (yttrium iron garnet), TmIG (thulium iron garnet), TbIG (terbium iron garnet) and conducting oxide half-metals like LSMO (lanthanum strontium manganite). These materials exhibit several notable properties: ultra-low damping in YIG, robust perpendicular magnetic anisotropy in ultrathin TmIG, and nearly 100% spin polarization in LSMO. Due to these exceptional characteristics, they hold strong potential for next-generation energy-efficient spin-based technologies. We propose to explore three interconnected research directions by integrating different classes of magnetic oxide materials: OBJECTIVE 1: SPIN PUMPING FROM HALF-METALLIC LSMO ACROSS ITS TRANSITION TEMERATURE While spin pumping has been widely studied in insulating systems like YIG and metallic ferromagnets (e.g. Co, Py, etc.), its behavior in half-metallic magnets such as LSMO remains largely unexplored. LSMO exhibits a ferromagnetic-to-paramagnetic transition near temperature ~360 K, offering a unique opportunity to study fluctuation-mediated spin pumping near this transition. This study can provide new insights into the spin current generation in oxide-based spintronics. OBJECTIVE 2: VOLATGE-CONTROLLED MAGNETIC ANISOTROPY (VCMA) IN INSULATING MAGNETIC OXIDES VCMA is a critical mechanism for reducing switching current density in spintronic devices and lowering power consumption. So far, VCMA has been explored predominantly in conducting magnetic systems (e.g., FeCoB/MgO), where current shunting poses a major limitation. We aim to study VCMA in insulating magnetic oxides such as YIG, TmIG, and TbIG. This could enable low-power magnetic memory devices without leakage currents. OBJECTIVE 3: MAGNON-MAGNON COUPLING IN FERROMAGNETIC INSULATOR/HALF-METAL BILAYES Magnon-Magnon Coupling (MMC) arises from the dynamic coupling between magnons in adjacent magnetic materials. While this phenomenon has been observed in systems such as YIG/Py, it has not been experimentally studied in bilayers composed of ferromagnetic insulators and half-metals. We propose to investigate MMC in YIG/LSMO heterostructures, leveraging the high spin polarization of LSMO. Furthermore, we will study the temperature dependence of this effect to probe the influence of spin fluctuations near the magnetic phase transition. EXPERIMENTAL APPROACH: All oxide materials will be grown using pulsed laser deposition (PLD). SP, VCMA, and MMC will be characterized via ferromagnetic resonance (FMR) under varying temperatures and gate voltage. This comprehensive study aims to combine the advantages of insulating magnetic oxides with the spin polarization of half-metals to develop novel spintronic devices with efficient spin current generation, tunable anisotropy, and dynamic coupling - key features for future low-power memory and logic applications.