Recent progress in high-resolution magnetic imaging using scanning probe techniques

We have applied magnetic force microscopy (MFM) and spin-polarized scanning tunnelling spectroscopy (SP-STS) in ultrahigh vacuum (UHV) to study the magnetic domain structure of Co/Au(111) and Gd/W(110), respectively. A new measurement mode will be presented which minimizes possible accidental interactions between the probe tip and the sample in UHV-MFM. This allows the investigation of the well known spin reorientation transition of Co films grown on Au(lll) at nanometre-scale spatial resolution. Details of domain walls and the domain structure as a function of CO coverage are studied. Spin-polarized tunnelling is realized by using an Fe-coated W tip and a sample which exhibits an exchange-split surface state. Magnetic domain imaging with a spatial resolution below 20 nm is demonstrated for Gd/W(IIO). The observed bias dependent spin polarization of Gd(0001) is in good agreement with spin-resolved inverse photoemission spectroscopy results.