MSE Fall Seminar Series: John Heron, University of Michigan
Description
"Electric field control of magnetism for energy efficient memory and logic devices"
John Heron
Department of Materials Science and Engineering, University of Michigan
Conventional CMOS based logic and data storage devices require the shuttling of electrons for data processing and storage. As these devices are scaled to increasingly smaller dimensions in the pursuit of speed and storage density, significant energy dissipation has become a center stage issue for the microelectronics industry. Instead, a new paradigm for logic and memory has emerged harnessing the long-range order of charge, spin, and strain in materials (so called ferroic materials) that exhibit collective thresholding switching and non-volatility which enables new scaling trends in energy dissipation per operation. My group investigates and engineers the interplay between spin, charge, lattice, and orbital degrees of freedom in intrinsic and artificial systems for novel device functions. Here I will discuss the advances we have made in composite multiferroics composed of a magnetostrictive ferromagnet and a piezoelectric ferroelectric which hold promise for magnetic field sensors and energy efficient beyond-CMOS logic by harnessing magnetoelectric transduction. Enhancing device performance requires highly magnetostrictive materials, however, relatively little attention has been given to engineering magnetostriction in thin films. Here I will present a novel means to boost the magnetostriction, and by extension the magnetoelectric coefficient, by extending the phase stability of a chemically disordered metastable phase of Fe1-xGax thin film alloys. Transport-based magnetoelectric characterization of a Fe1-xGax - [Pb(Mg1/3Nb2/3)O3]0.7-[PbTiO3]0.3 (PMN-PT)composite multiferroic heterostructure shows are reversible 90 electrical switch of magnetic anisotropy and a large room temperature converse magnetoelectric coefficient of ~2×10-5 s m-1. I will conclude the presentation with advances toward realizing sub 250 mV write voltage and sub 100 aJ energy dissipation per operation performance.
For Webinar information please contact Kyle Page (kmp265@cornell.edu)