GMR giant magnetoresistance

The third example of new technology with increasing interest is electrodeposition of multilayers. For example, Schlesinger et al. (29) have shown that this technology can be applied to produce systems with nanometer-scale structural and compositional variations. Giant magnetoresistance (GMR) in electrodeposited Ni/Cu and Co/Cu multilayers was reported by Schlesinger et al. (28). Those constructs have a number of immediate applications in the areas of sensors as well as nanometer-scale electronic circuitry. For a more complete reference fist as well as apphcations to date, see the review article by Schwartzacher and Lashmore (30). 

The electronic and magnetic properties of nanolayers are important in devices formed from electronic materials that are more conventional. We have already discussed quantum well lasers (see Chapter 8) and giant magnetoresistance (GMR) devices used for hard disk read heads (see Chapter 9). Quantum well lasers may be an important component of light-based computers. Other possibilities include magnets with unusual properties (Section 11.2). 

It is also possible to electrodeposit multilayers in cylindrical pores of a suitable etched polymer membrane. Typically, wires with diameters of about 100 nm and length of 5-10 fim can be obtained. The deposition cycles are similar to the ones described above. Magnetoresistance [this is a term describing the relative decrease (increase) in electrical resistance of a material when subjected to a magnetic field longitudinally (transversely) to the current flow] measurements with the current perpendicular to the planes are possible. In addition, giant magnetoresistance (GMR defined below) effects may be observed as well. 

An effect of external factors on giant magnetoresistance (GMR) for asymmetric layer structure metal/polymer/non-magnetic metal was investigated. The magnetostriction, galvanomagnetic effects and instability of contacts are not the reasons for GMR appearance. The conclusion on the injective nature of the GMR effect was drawn. 

Enhanced magnetoresistive effect, called giant magnetoresistance (GMR) effect, was observed in magnetic layered structures consisting of magnetic/nonmagnetic metal multilayers [131,132], First, GMR multilayers were produced by vacuum deposition... 

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