Magnetoresistive Materials and Devices

Summary

We have in this chapter discussed some magnetoresistive phenomena, and how some of them are applied, in particular in magnetic recording. The phenomena and their current applications form a fascinating and challenging mixture of research ranging from quantum mechanics to materials physics and state-of-the-art processing technologies. The main current applications of magnetoresistance are in magnetic field sensing, with perhaps some of the most advanced devices, such as spin valves and magnetic tunneling junctions, in the area of magnetic recording. However, current device applications are to some extent limited both by the magnitude and sensitivity of the magnetoresistive effect on the one hand, and by the complex sets of materials and concomitant complex and expensive processing technologies. Semiconductor spintronics opens up the possibility of both better materials and processing control, as well as the possibility of completely novel devices and applications. It remains to be seen when such devices and applications will actually be realized, but it is certain that research in semiconductor spintronics will remain an active and stimulating field at the intersection of basic physics, materials research, and engineering for a long time to come.