Simulations of Complex Order in Thin-Film Magnetic Systems

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The main purpose of my research is to gain a deeper understanding of complex magnetic materials for nano-device applications which can facilitate improvements in their functionality. From the enhancement of high-temperature superconductivity to enabling terabytes of data storage through computer hard-drive sensors devices, fundamental understanding of magnetic structures and materials has led to radical new insights and technological innovations in recent decades. New magnetic materials continue to be discovered and investigations of their basic properties will provide a path for their applications in future technologies. Through extensive computer modeling, we will reveal novel magnetic phases arising from newly characterized crystal structures that are relevant to nano-scale magnetoresitive-based sensors. These represent avenues of research which bridge fundamental and applied physics. Our work will provide a microscopic (atomic-spin level) understanding of exchange pinning in hard-drive spin-valve magnetic sensor technology which has eluded researchers for the past twenty years. This understanding will facilitate methods to improve sensor stability and performance. The fundamental crystal geometry of interest in these materials is the triangle which gives rise to magnetic frustration and exotic magnetic states that interact with electronic material properties. A very large number of novel magnetic crystal structures have been synthesized with this underlying triangular unit and their properties have yet to be fully explored. The efforts of my group will also reveal the underlying mechanisms responsible for unusual magnetoelectric behavior in these new materials which respond to both applied magnetic and electric fields and are being evaluated for technological applications. This understanding is critical for the future growth of data storage capacity. A major influence on my research activity is on-going collaborations with hard-drive manufacturer Western Digital Corporation as well as with experimental groups at Memorial and Manitoba. Interactions with other researchers in Canada and abroad are being facilitated by the organization which I co-founded and now lead, Magnetic North, which sponsors regular international workshops. The research activity in my group will enable associated undergraduate and graduate students to develop critical programming and high performance computing skills relevant to industry that will help drive the expansion of technology in Canada.