Spintronic materials and devices: past, present and future!

Spintronics utilizes the electron's spin to create useful sensors, memory and logic devices with properties not possible with charge based devices. This paper reviews the past successes, and the current and future prospects of spintronic materials and devices. A magnetic random access memory (MRAM) based on a magnetic tunnel junction memory cell promises a high performance memory with high density, speed and nonvolatility: a recent 16 Mb MRAM demonstration chip is described. Two and three terminal tunnel-junction based sources of highly spin polarized current are described as one component of possible spintronic logic devices, which have the potential for much lower power operation than charge based devices. Finally, we discuss a concept for a solid-state memory based on advanced spintronic concepts which promises as much as a hundredfold increase in the capacity of solid state memories, rivaling the capacities of hard disk drives but with no moving parts.