Development of an UHV-SMOKE System Using Permanent Magnets

Abstract

We have developed an ultra-high-vacuum surface-magneto-optical Kerr effect (UHV-SMOKE) system which utilizes a pair of Sm-Co permanent magnets to apply magnetic field as large as ±0.23 T. The magnetic field can be applied parallel and perpendicular to the sample surface to perform longitudinal and polar Kerr effect measurements, respectively. The field strength can be changed by rotating the magnet pair symmetrically. The system can be operated in the vacuum of ∼ 10^-11 Torr and at the temperature as low as ∼ 20 K. We have adopted the Faraday-cell modulation technique to obtain the detection sensitivity of Kerr rotation angle as small as 10^-4 degree. Its capability is demonstrated by measuring the hysteresis loops of Co layers deposited on Ag(111) film. [DOI: 10.1380/ejssnt.2010.298]