Magnetoresistance is an effect in which the resistance of amagnetic film, or a multilayer film, varies as a function of applied magnetic field. This has intersting technological applications and we have an apparatus designed to measure this effect.
Scientific discussion around the magnetoresistance measurement apparatus
The magnetoresistance curve is hysteretic, i.e. the value of the resistance depends on whether we are ramping the field up or down. When we measure magnetoresistance we ramp the applied field to a value high enough to acheive magnetization saturation, then gradually scan the applied field all the way to negative saturation, and back. When we plot the resistance as a function of applied field we obtain a curve similar to the "M" in our logo in the upper left corner of this page.