STRONG HALL VOLTAGE MODULATION IN HYBRID FERROMAGNET SEMICONDUCTOR MICROSTRUCTURE/

We present a new magnetoelectronic device consisting of a mu m-scale s emiconductor cross junction and a patterned, electrically isolated, fe rromagnetic overlayer:with in-plane magnetization. The large local mag netic field emanating from the edge of the thin ferromagnetic film has a strong perpendicular magnetic component, B-perpendicular to(r), whi ch induces a Hall resistance, R-H,in the microjunction. External appli cation of a weak in-plane magnetic field reverses the magnetization of the ferromagnet and with it B-perpendicular to(r), thus modulating R- H. Our data demonstrate that this strong ''local'' Hall effect is oper ative at both cryogenic-and room temperatures, and is promising for de vice applications such as field sensors or integrated nonvolatile memo ry cells. (C) 1997 American Institute of Physics.