▎ 摘　　要

NOVELTY - Extraordinary magnetoresistance (EMR) sensor includes graphene layer (310) on a substrate (300); and ferromagnetic biasing layer (304) on the substrate between the substrate and graphene layer and having its magnetic moment oriented perpendicular to the planes of the ferromagnetic biasing layer and the graphene layer. USE - EMR sensor used as magnetoresistive read head in magnetic recording disk drive. ADVANTAGE - The sensor has ferromagnetic biasing layer that provides the desired static magnetic biasing field and is located in close proximity to the graphene sense layer without causing electrical shorting of the graphene sense layer. The graphene sense layer is located on layers that provide electrostatic gating through the electric field effect and static magnetic field bias. The layered structure ensures that the graphene sense layer is not electrically shorted by the ferromagnetic biasing material used to provide the electrostatic gating and static magnetic field bias. The materials comprising the layered structure allow for the growth of graphene layer, providing for relatively easy fabrication of the sensor. The spacer material separating the graphene sense layer and the ferromagnetic biasing material increases the sensitivity of the sensor by reducing charge impurity scattering and hence increasing charge carrier mobility. The sensor allows the use of a much smaller magnet that localizes the magnetic field in a small region near the sensor, eliminating fields from the biasing layer at the write head and reducing the size of the magnetic field at the media. DETAILED DESCRIPTION - EMR sensor comprises substrate; graphene layer (310) on the substrate (300); ferromagnetic biasing layer (304) on the substrate between the substrate and graphene layer and having its magnetic moment oriented perpendicular to the planes of the ferromagnetic biasing layer and the graphene layer; electrically insulating underlayer (308) between the ferromagnetic biasing layer and graphene layer; pair of current leads in contact with the graphene layer for the injection and extraction of current flowing in the graphene layer; electrically conductive shunt in contact with the graphene layer through which current flows in the absence of an external magnetic field; and pair of voltage leads in contact with the graphene layer for the detection of a voltage change in response to a decrease in shunted current in the presence of an external magnetic field applied perpendicular to the plane of the graphene layer. DESCRIPTION OF DRAWING(S) - The drawing is a cross-sectional view of layers of graphene magnetic field sensor showing the ferromagnetic biasing layer below the graphene sense layer. Substrate (300) First seed layer (302) Ferromagnetic biasing layer (304) Electrically insulating underlayer (308) Graphene layer (310)