The development of novel magnetic materials with distinct properties for spintronic technology
Date
2025
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Publisher
University of Delaware
Abstract
Efficient switching of magnetization is a central challenge in spintronic technology. This thesis explores novel material platforms with enhanced performance, aiming to overcome key challenges such as the need for high charge-to-spin conversion efficiency and bias-free out-of-plane magnetization switching. Three classes of materials are systematically investigated: the noncollinear antiferromagnet Mn₃Sn, the heavy metal alloy RuₓPt₁₋ₓ, and altermagnetic RuO₂. Generation of unconventional polarized spin currents is demonstrated in Mn₃Sn, attributed to its cluster multipole structure. In the RuPt alloy system, structural phase evolution and spin Hall angle (SHA) variations are analyzed through X-ray diffraction and both MOKE and ST-FMR techniques, revealing a SHA 0.117 in 38% Ru composition. Lastly, the potential altermagnetic nature of RuO₂ is examined via cross-strip MOKE scanning, THz emission spectroscopy, and magnetic force microscopy. While no direct evidence of altermagnetism is observed, several unexplained phenomena suggest the presence of nontrivial thermoreflectance effects. This work not only introduces promising candidate materials for spintronic applications but also deepens the understanding of spin transport in complex magnetic systems.
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Keywords
Altermagnetics, Antiferromagnets, Spin hall effect, Spintronics, Spin-Torque Ferromagnetic Resonance