Spintronics

Abstract

So far in our discussion of the band picture of materials, we have ignored the spin of an electron. The magnetic properties of metals like Fe, Ni, Co, etc, and magnetic semiconductors like GaMnAs, MnAs, etc. may directly be attributed to the spin, which is explored in this chapter.

Appendices

Problems

7.1 What is a ferromagnetic material? Give an example.

7.2 What is an antiferromagnetic material? Give an example.

7.3 What is the superparamagnetic limit for a nanomagnet?

7.4 Give an example of a soft magnet.

7.5 Give an example of a hard magnet.

7.6 Amongst CIP and CPP configurations, which has a higher GMR ratio?

7.7 For a GMR device, $I_\mathrm{P} = 1.05$ mA and $I_\mathrm{AP} = 1$ mA, calculate its GMR ratio.

7.8 For an MTJ device, $I_\mathrm{P} = 3\,\upmu$A and $I_\mathrm{AP} = 2$ nA, calculate its TMR ratio. Consult the literature and comment on the current values in comparison with the GMR device in Problem 7.7.

7.9 What are the advantages of STTRAM? What are the bottlenecks?

7.10 Give an example of how single molecule magnets (SMM) are being used in nature or man-made structures.

Research Assignment

R7.1 Write a one-page summary about nanomagnetism and its applications.

R7.2 Communication applications like fiber optics, wireless technologies, sensors/detectors, light emitting diodes, LASER devices, have benefited from the use of nanomaterials and nanotechnology. Pick a topic of your choice about how communication technologies have benefited from the nano age, and write a one-page summary.