Magnetoresistance in Graphene

• Nobel laureate Andre Geim has recently discovered that Graphene displays an anomalous giant magnetoresistance (GMR) at room temperature.

About GMR                                                                                       

• Magnetoresistance is the tendency of a material to change the value of its electrical resistance in an externally-applied magnetic field.
• Giant Magnetoresistance (GMR) is the large change in the electrical resistance which is induced by the application of a magnetic field to thin films composed of alternating ferromagnetic and nonmagnetic layers.
  • When materials are magnetised in same direction, electrical resistance in the conductor is low.
  • When directions are opposite each other, resistance increases.
• Application of GMR: Hard disk drives and magnetoresistive RAM in computers, biosensors, automotive sensors, microelectromechanical systems, and medical imagers.
• New study has found that a graphene-based device, unlike conventional counterparts, wouldn’t need to be cooled to a very low temperature to sense magnetic fields.

About Graphene

• Graphene is ‘a two-dimensional single-atom-thick layer of carbon atoms bonded in a hexagonal honeycomb lattice structure.
• It has exceptionally high tensile strength, electrical conductivity, transparency, and thinnest two-dimensional material in the world.
• It is almost perfectly transparent since it only absorbs 2 percent of light.
• It is extracted from graphite.
• Applications include Energy (Solar cell, Fuel cell, Super computers etc); Sensor, Bio-sensor; Biomedical (diagnostic, drug delivery etc); Environment treatment etc