nanomagnetism and spintronics, 2009, p.344

[...]... TMs Cr, Fe and Co, and the DOS of Cu The electronic states are composed of wide s-bands and narrow d-bands The d-part of the DOS is high because the d-states are localized near atoms The s- and d-states hybridize to form complicated electronic states GMR, TMR and BMR 19 E Cu − + − EF − + + Fe Cr + − Co FIGURE 1 Schematic density of states (DOS) of Cr, Fe, Co and Cu þ and À indicate majority and minority... a-parameters for TM and noble metal impurities in Fe (as an example host metal) as a function of the number of 4s þ 3d electrons of the impurities [30] of a broad s-like band and narrow d-like bands with a mixing between the s- and d-bands Taking Fe as the host metal for example, the electronic state of TM–Fe alloys may be given by a random distribution of d-levels ETM and EFe of the TM and Fe atoms, respectively... “Magnetic Multilayers and Giant Magnetoresistance” Springer, Berlin Mills, D L., and Bland, J A C (eds.) (2006) In Nanomagnetism, Ultrathin Films, Multilayers and Nanostructures” Elsevier, New York Overview 13 [19] Shinjo, T., and Yamamoto, H (1990) J Phys Soc Jpn 59, 3061 [20] Hosoito, N., Ono, T., Yamamoto, H., Shinjo, T., and Endoh, Y (1995) J Phys Soc Jpn 64, 581 [21] Maekawa, S., and Shinjo, T (eds.)... [32], carbon nanotubes and graphenes, and organic molecules, although they may become key players for future spintronic devices This book is not able to cover whole relevant areas of nanomagnetism and spintronics However, the author hopes that this book will be useful for the readers to recognize the significance of this field It is certain that the field, nanomagnetism and spintronics, will continue... Kohno and Tatara in Chapter 5 Studies on dynamical behaviour of magnetic domain wall with micro-magnetic simulation are presented in Chapter 6 by Thiaville and Nakatani Finally in Chapter 7, Ohno and Matsukura survey recent developments on ferromagnetic III–V compound semiconductors, typically Mn-substituted GaAs Their electric and magnetic properties are surveyed and novel phenomena relating to spintronics,. .. confirm the model directly by experiment, since s" and s# cannot be separated independently from the s data However, Fert and Campbell [23, 24] have approached the problem by measuring the residual resistivity and temperature dependence for various binary and ternary alloys and succeeded in deducing the ratio r#/r" (¼s"/s#) for diluted alloys of Fe, Co and Ni metals The ratio is referred to as the a-parameter... indicates the effective bandwidth of the 3d-bands [25] 2 tÀ1 ¼ 5ð2p=ł ÞNi Vsd Dds ðEF Þ; h s ð3Þ where Vsd represents s–d mixing between the conduction state and localized d-states of impurities, and Dds(EF) is the DOS of impurities at EF with spin s The factor 5 comes from the degeneracy of the d-states of TM impurities Equation (3) is similar to Eq (2) with Vs and Ds replaced by Vsd and Dds This is to... 54, 225 ¨ [26] Maekawa, S., and Gafvert, U (1982) IEEE Trans Magn 18, 707 [27] Tezuka, N., and Miyazaki, T (1996) J Appl Phys 79, 6262 [28] Moodera, J S., and Kinder, L B (1996) J Appl Phys 79, 4724 [29] Yuasa, S., Nagahama, T., Fukushima, A., Suzuki, Y., and Ando, K (2004) Nat Mater 3, 868 [30] Parkin, S S P., Kaiser, C., Panchula, A., Rice, P M., Hughes, B., Samant, M., and Yang, S H (2004) Nat Mater... metal and a non-magnetic B metal is shown in Fig 8 The thickness of each layer is 1–10 nm and the number of layers ranges from 3 (for trilayers) to about 100 Fe, Co, Ni and their alloys are frequently used for the ferromagnetic A layers, while d A dЈ B FIGURE 8 Schematic figure of magnetic multilayers with ferromagnetic A and non-magnetic B layers d and d0 indicate the layer thickness GMR, TMR and BMR... Ta W Re Os Ir Pt Au Hg FIGURE 9 Atomic distance between nearest-neighbour sites and lattice structures in 3d, 4d and 5d transition metals Circles, squares and hexagons under the figure show that the crystal structures of metals are fcc, bcc and hcp, respectively non-magnetic TMs such as Cr and Ru or noble metals Cu, Ag and Au are used for the non-magnetic B layers To fabricate high-quality magnetic . micro- and nanoscale samples have progressed rapidly, the field of spin electronics or spintronics has been developed, where the coupling of electron spin and charge plays an important role. In paramagnets,. switching and spin-torque diode effect, in GMR and TMR junctions are described. Basic physical concepts and feasi bility for application are argued. In Chapter 4, Ono and Shinjo explain experimental. low resistivity of CPP systems may be a merit from a viewpoint of application. Therefore, further extension of CPP-MR studies is awaited. CPP experiments have evidenced that the application of nanoscale