Detection of ferromagnetic particles using spin valve sensors.

Authors :: Lui, L. W. Y.
Tan, Y. Y.
Li, K. B.
Sow, C. H.
O’Shea, S. J.
Source :: Journal of Applied Physics. 8/15/2006, Vol. 100 Issue 4, p044909. 6p. 3 Color Photographs, 3 Diagrams, 4 Graphs.
Publication Year :: 2006
Abstract: We have attached single ferromagnetic particles of 8 μm diameter to the tips of microfabricated atomic force microscope cantilevers. These cantilevers were magnetized to fix the magnetization direction of the ferromagnetic particles and scanned in a controlled manner over a spin valve structure of dimension 12×8 μm2. Two dimensional image scans representing the change in resistance of the spin valve due to a scanning bead were obtained. The results are explained using a simple model where the scanning bead is treated as a pure dipole. [ABSTRACT FROM AUTHOR]