TECHNICAL: There has been significant progress in the understanding of spin-transfer torque (STT) effects in nanoscale magnetic structures. STT is capable of switching the magnetic state of a magnetic structure by the passage of a spin-polarized current, offering advantages in terms of device simplicity and power consumption. Most STT research has been directed towards the development of magnetic random access memories. However, the possible applications of STT are much wider than this, including for example combined programmable logic and memory devices. Progress in this field is based on the development of new magnetic materials and an understanding of the influence of the processing conditions, composition, microstructure and patterning on the magnetic properties of the materials. The intellectual merit of this SGER award is to investigate STT effects in metal multilayer nanostructures with different layer sequences and compositions, through building functional magnetic nanostructures. PI will design a device that will combine STT effects with magnetostatic interactions to show how data can be written, transmitted, and processed within a single magnetic device. Multilayer stacks chosen for patterning will contain a free magnetic layer separated from a synthetic-antiferromagnet pinned layer by a non-magnetic metal or an insulator. The critical current densities required for STT operation will be optimized by considering the influence of the cell shape, multilayer stack, patterning conditions and microstructure. The focus will be on how the choice of metal alloys and layer sequence in the magnetic multilayer affects the performance of the device, and the information this yields about the mechanism of STT. NON-TECHNICAL: The broader impacts are to train a researcher and undergraduate students in the field of magnetic nanostructures and STT. The researcher will work with 2 ? 4 undergraduates during the course of the project. The undergraduates will participate through the undergraduate research opportunities (UROP) program, or as senior thesis project students, or through a REU program. In addition, the researcher and the PI plan to work with at least one teacher during a summer RET program, and incorporate findings from the project into graduate and undergraduate classes.
