Types of Magnetoresistance

Magnetoresistance is the tendency of a material (preferably ferromagnetic) to change the value of its electrical resistance in an externally-applied magnetic field. There are a variety of effects that can be called magnetoresistance: some occur in bulk non-magnetic metals and semiconductors, such as geometrical magnetoresistance, Shubnikov de Haas oscillations, or the common positive magnetoresistance in metals.

ordinary magnetoresistance, depending on the structure of the electron orbitals at the Fermi surface: i) In metals with closed Fermi surfaces, the electrons are constrained to their orbit in k space and the effect ofthe magnetic field is to increase the cyclotron frequency ofthe electron in its closed orbit.