The Effect of Concentration Gradients of Impurities on the Temperature Dependence of the Spin—Lattice Relaxation Time in Lithium and Beryllium

Abstract

Messurements are presented of the conduction electron spin resonance linewidths for various samples of lithium and beryllium a t frequencies of 9.27 GHz and 33 and 80 MHz, the samples having dimensions which are large compared with the appropriate skin depth.An increase in the linewidths and certain line shape anomalies as measured a t 9.27 GHz a t low temperatures, are discussed in terms of relaxation in an impure surface layer. A value of xs = 1.6 x c.g.s. units has been deduced for the spin susceptibility of beryllium.On prBsente ici, aux frkquences de 9,27 GHz, de 33 MHz et de 80 MHz, les spectres des rksonances magn6tiqnes klectroniques de divers Bchantillons de lithium et de bBryllium ayant des dimensions qui sont grandes en consideration de la profandeur de la peau. On discute les augmentations de raies, et certaines formes irrkgulibres, observBes B une frbquence de 9,27 GHz et aux tempbratures basses, suivant un mecanisme de relaxation d'une surface impure. On dBduit une valeur de xs = 1,6 x c.g.s. pour la susceptibilite Blectronique de bkryllium.

Spintronics: Fundamentals and applications

“…Interesting results were obtained by injecting spin into superconductors. Using YBa 2 Cu 3 O 7Ϫ␦ , for example, data were interpreted (Fi et al, 2002) to infer that the in-plane spin relaxation time is unusually long, 81 A list of selected metals includes Li (Feher and Kip, 1955;Orchard-Webb et al, 1970;Damay and Sienko, 1976); Na (Feher and Kip, 1955;Vescial et al, 1964;Kolbe, 1971); K (Walsh et al, 1966a); Rb (Schultz and Shanabarger, 1966;Walsh et al, 1966b); Cs (Schultz and Shanabarger, 1966;Walsh et al, 1966b); Be (Cousins and Dupree, 1965;Orchard-Webb et al, 1970); Mg (Bowring et al, 1971); Cu (Schultz and Latham, 1965;Lubzens and Schultz, 1976a;Monod and Schultz, 1982); Au (Monod and Já nossy, 1977); Zn (Stesmans and Witters, 1981); Al (Lubzens and Schultz, 1976b); graphite (Wagoner, 1960;Matsubara et al, 1991) about 100 s at low temperatures to 1 s close to the superconducting transition temperature. For quasiparticles moving along the c axis, s is more likely to be the usual spin-orbit-induced spin relaxation time, having values of 10-100 ps.…”

“…II) was also used to measure τ s for various metals, including Al (Jedema et al, 2002a(Jedema et al, ,b, 2003Johnson and Silsbee, 1985), Au (Elezzabi et al, 1996), Cu (Jedema et al, 2001(Jedema et al, , 2003, and Nb (Johnson, 1994). In addition to CESR and spin injection, information about spin-orbit scattering times τ so (see below) in various (but mostly 81 A list of selected metal includes Li (Damay and Sienko, 1976;Feher and Kip, 1955;Orchard-Webb et al, 1970); Na (Feher and Kip, 1955;Kolbe, 1971;Vescial et al, 1964), K (Walsh et al, 1966a); Rb (Schultz and Shanabarger, 1966;Walsh et al, 1966b); Cs (Schultz and Shanabarger, 1966;Walsh et al, 1966b); Be (Cousins and Dupree, 1965;Orchard-Webb et al, 1970), Mg (Bowring et al, 1971); Cu (Lubzens and Schultz, 1976a;Monod and Schultz, 1982;Schultz and Latham, 1965); Au (Monod and Jánossy, 1977); Zn (Stesmans and Witters, 1981); Al (Lubzens and Schultz, 1976b); graphite (Matsubara et al, 1991;Wagoner, 1960); Rb 3 C 60 (Jánossy et al, 1993); MgB 2 (Simon et al, 2001). Various data on CESR τs are collected in (Beuneu and Monod, 1978;Monod and Beuneu, 1979).…”