IEEE Distinguished Lecturers in BCMaterials Invited Talks

Michael McHenry. Materials Science and Engineering Department, Carnegie Mellon University

Michael McHenry´s talk will focus on the framework for developing high frequency (f) magnetic materials for grid  integration of renewable energy sources bridging the gap between materials development, component design, and system analysis. Examples from recent efforts to develop magnetic technology for lightweight, solid-state, medium voltage (>13 kV) energy conversion for MWscale power applications will be  llustrated. The potential for materials in other energy applications (motors, cooling, sensors, RF metal joining, etc.) will also be introduced. The scientific framework for nanocomposite magnetic materials that make high frequency components possible will be discussed in terms of the materials paradigm of synthesis  à structure  à properties à performance. In particular, novel processing and the control of phase  transformations and ultimately nanostructures has relied on the ability to probe structures on a nanoscale. Examples of nanostructural control of soft magnetic properties will be illustrated.

Adekunle Adeyeye will talk about artificial ferromagnetic nanostructures with periodic lateral contrasts in magnetization, which are known as  magnonic crystals” (MCs), conceived as the magnetic analogue of photonic crystals.

Recently, there is growing interest in the fundamental understanding of the spin wave propagation in MCs because of their huge potential in a wide range of applications such as microwave resonators, filters and spin wave logic devices. With advances in controlled nanofabrication techniques, it is now possible to synthesize highquality periodic bi-component magnetic nanostructures with precisely controlled dimensions. The band spectrum of MCs consists of allowed states magnonic bands and forbidden states (magnonic gaps) that can be tuned by magnetic fields or geometrical parameters. We have shown that MCs represent a perfect system for studying excitations on disordered periodical lattices because of the possibility of controlled variation in the degree of disorder by varying the applied magnetic field . We have also demonstrated functionality of magnetic logic based on a reconfigurable MC in the form of a meander-type ferromagnetic nanowire . A ferromagnetic resonance method employing a microscopic coplanar waveguide was used to detect the logic state of the structure coded in its magnetic ground state.