Giant magnetoresistance

Metallic multilayers. In Section 7.4, we have met the recent discovery of multilayers of two kinds of metal, or of a metal and a non-metal, that exhibit the phenomenon of giant magnetoresistance. This discovery is one reason why the preparation and exploitation of such multilayers have recently grown into a major research field. 

ELECTRICAL CONDUCTIVITY OF INHOMOGENEOUS SYSTEMS APPLICATION TO MAGNETIC MULTILAYERS AND GIANT MAGNETORESISTANCE... 

W. H. Butler, X.-G. Zhang, D. M. C. Nicholson, T. C. Schulthess, and J. M. MacLaren, First Principles Calculations of Elecuical Conductivity and Giant Magnetoresistance of ColCulCo Spin Valves ,... 

There has been extensive recent use of track-etched membranes as templates. As will be discussed in detail below, these membranes are ideal for producing parallel arrays of metal nanowires or nanotubules. This is usually done via electroless metal deposition [25], but many metals have also been deposited electrochemically [26]. For example, several groups have used track-etched templates for deposition of nanowires and segmented nanowires, which they then examined for giant magnetoresistance [27-29]. Other materials templated in the pores of track etch membranes include conducting polymers [30] and polymer-metal composites [31]. 

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). 

Figure 17.9. Maximum (saturation) value of the giant longitudinal magnetoresistance (GMR) in electrochemically grown Co/Cu multilayers as a function of Cu layer thickness. Cobalt layer thickness is held constant at 20 A per layer. The continuous curve is the corresponding RKKY function. (From Ref. 6b, with permission from the Electrochemical Society.)...

Ishii K, Fujiwara A, Suematsu H, Kubozono Y (2002) Ferromagnetism and giant magnetoresistance in the rare-earth fullerides Eug xSrxCgo. Phys Rev B65 134431/1-6... 

Baibich MN, Broto JM, Fert A, Nguyen Van Dau F, Petroff F, Etienne P, Creuzet G, Friederich A, Chazelas J (1988) Giant magnetoresistance of (001)Fe/(001)Cr magnetic superlattices. Phys Rev Lett 61 2472-2475... 

Parkin SSP, Kaiser C, Panchula A, Rice PM, Hughes B, Samant M, Yang SH (2004) Giant tunneling magnetoresistance at room temperature with MgO(lOO) tunneling barriers. Nat Mater 3 862-867... 

Yuasa S, Nagahama T, Fukushima A, Suzuki Y, Ando K (2004) Giant room-temperature magnetoresistance in single-crystal Fe/MgO/Fe magnetic tunnel junctions. Nat Mater 3 868-871... 

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