Spin-polarized quantum well states

Highly-quality Cu/Co/Cu(100) quantum wells an grown in a newly-constructed growth chamber that contains RHEED, LEED, SMOKE, MBE, and sputter depositio n facilities. The low defect density of the fee Co(100) layers is evidenced by a record low coercivity of 0.7 Oe, which indicates minimal pinning of t he domains. Spin-polarized, angle-resolved photoemission spectra are obtain ed using synchrotron radiation from an undulator. They exhibit quantum well states of minority spin character which are derived from states at the nec k of the Cu Fermi surface. Such states have been predicted to dominate the magnetic coupling in multilayers. They have been difficult to observe becau se their short wavelength requires atomically-sharp interfaces. The key to obtaining high quality films with sharp interfaces is deposition at low tem perature (approximate to 175 K) and annealing to room temperature. (C) 1999 Elsevier Science B.V, All rights reserved.