Use of voltage pulses to detect spin-polarized tunneling.

The present letter describes a method to make a spin-polarized scanning tunneling microscopy tip by applying voltage pulses between a W tip and a magnetic sample. This spin-polarized tip has the similar characteristics as an Fe-coated W tip, which was confirmed by observations of antiferromagnetically coupled ferromagnetic Mn(001) layers (> 3 ML) grown on an Fe(001) whisker at 370 K. Furthermore, we demonstrate that these voltage pulses can vary the tip magnetization direction. [ABSTRACT FROM AUTHOR]