Thursday, July 4, 2013

1307.0591 (Soo-hyon Phark et al.)

Superparamagnetic response of Fe-coated W tips in spin-polarized
scanning tunneling microscopy

Soo-hyon Phark, Jeison A. Fischer, Marco Corbetta, Dirk Sander, Jürgen Kirschner
We performed spin-polarized scanning tunneling spectroscopy on biatomic-layer-high Co nanoislands grown on Cu(111) in magnetic fields oriented normal to the sample surface, with Fe-coated W tips. Increasing the temperature from 10 to 30 K, we observe a reduced slope of the differential conductance around zero field. A quantitative analysis of the field- and temperature-dependent differential conductance data in the framework of superparamagnetism as described by a Langevin function gives an excellent description of the experimental results. The analysis suggests that a Fe nano-apex at the W tip, which is composed of 220-300 Fe atoms, determines the magnetic response of the tip.
View original:

No comments:

Post a Comment