Spin-dependent band structure, Fermi surface, and carrier lifetime of permalloy

Citation
Dy. Petrovykh et al., Spin-dependent band structure, Fermi surface, and carrier lifetime of permalloy, APPL PHYS L, 73(23), 1998, pp. 3459-3461
Citations number
29
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
00036951 → ACNP
Volume
73
Issue
23
Year of publication
1998
Pages
3459 - 3461
Database
ISI
SICI code
0003-6951(199812)73:23<3459:SBSFSA>2.0.ZU;2-C
Abstract
Angle-resolved photoemission is used to determine the energy bands of perma lloy (Ni0.8Fe0.2) and compare them to Ni, Co, and Cu. The energy and moment um resolution (approximate to 0.01 eV and approximate to 0.01 Angstrom(-1)) is high enough to resolve the magnetically split bands at the Fermi level that are responsible for spin-dependent conductivity and tunneling. For the Sigma(1) band we find the magnetic exchange splittings delta E-ex = 0.27 e V (0.23 eV for Ni), delta k(ex) = 0.16 +/- 0.02 Angstrom(-1) (0.12 +/- 0.01 Angstrom(-1) for Ni), the Fermi velocity upsilon(F up arrow) = (0.22 +/- 0 .02) 10(6) m/s (0.28 x 10(6) m/s for Ni, 0.33 x 10(6) m/s for fcc Co), and the widths delta k(up arrow) less than or equal to 0.11 Angstrom(-1) and de lta k(down arrow) = 0.24 Angstrom(-1). Compared to Ni, permalloy features a 27% larger magnetic splitting of the Fermi surface and an extremely short mean free path of 4-8 Angstrom for minority spins. (C) 1998 American Instit ute of Physics. [S0003-6951(98)01249-2].