In situ measurements of magnetoresistive effects in ferromagnetic microstructures by Lorentz microscopy

We report on a four point resistance measurement inside a transmission electron microscope and during the imaging process which uses a special developed specimen holder. Lorentz microscopy allows us to observe the micromagnetic configuration of the ferromagnetic samples. Two different imaging techniques, Fresnel imaging and differential phase contrast, are used. The latter one allows lateral magnetic resolution down to 10nm. We present experiments on ferromagnetic nickel strips where we can show the direct correlation between the appearance of magnetic domains and anisotropic magnetoresistance.