Imaging magnetic nanostructures by spin-polarized scanning tunneling spectroscopy

Spin-polarized scanning tunneling spectroscopy (SP-STS) using Gd- and Fe-co ated probe tips is investigated. The antiferromagnetic domain structure of perpendicularly magnetized Fe nanowires is imaged by using Gd-coated tips. The influence of an external magnetic field on the nanowire domain structur e is demonstrated. Magnetic saturation of the sample is observed at about 4 50 mT. While Gd-coated tips are sensitive to the out-of-plane magnetization direction, the Fe thin film tips were found to be magnetized in-plane, i.e . perpendicular to the tip axis. our results indicate that the shape anisot ropy of our thin film tips plays a minor role compared to the interface ani sotropies at the tip apex. (C) 2001 Elsevier Science B.V. All rights reserv ed.