Editing Hall effect (section)

===Anomalous Hall effect===
In [[ferromagnetism|ferromagnetic]] materials (and [[paramagnetism|paramagnetic]] materials in a [[magnetic field]]), the Hall resistivity includes an additional contribution, known as the '''anomalous Hall effect''' (or the '''extraordinary Hall effect'''), which depends directly on the [[magnetization]] of the material, and is often much larger than the ordinary Hall effect. (Note that this effect is ''not'' due to the contribution of the [[magnetization]] to the total [[magnetic field]].) For example, in nickel, the anomalous Hall coefficient is about 100 times larger than the ordinary Hall coefficient near the Curie temperature, but the two are similar at very low temperatures.<ref>{{cite journal| journal=Phys. Rev. |volume=95 |pages=1154–1160 |year=1954 |author=Robert Karplus and J. M. Luttinger |title=Hall Effect in Ferromagnetics |doi=10.1103/PhysRev.95.1154| issue=5|bibcode = 1954PhRv...95.1154K }}</ref> Although a well-recognized phenomenon, there is still debate about its origins in the various materials. The anomalous Hall effect can be either an ''extrinsic'' (disorder-related) effect due to [[Spin (physics)|spin]]-dependent [[scattering]] of the [[charge carrier]]s, or an ''intrinsic'' effect which can be described in terms of the [[geometric phase|Berry phase]] effect in the crystal momentum space ({{math|''k''}}-space).<ref name="sinitsyn-08jpa">{{cite journal|title=Semiclassical Theories of the Anomalous Hall Effect|author=N. A. Sinitsyn|journal=Journal of Physics: Condensed Matter|volume=20|year=2008|pages=023201|arxiv=0712.0183|doi=10.1088/0953-8984/20/02/023201|bibcode = 2008JPCM...20b3201S | issue=2 |s2cid=1257769}}</ref><!-- N.A. Sinitsyn 2008 J. Phys.: Condens. Mater. '''20''' 023201 -->