Matteucci effect

Matteucci effect is the creation of a helical anisotropy of the magnetic susceptibility of a magnetostrictive material when subjected to a torque. It is one of the magnetomechanical effects, which is thermodynamically inverse to Wiedemann effect.{{cite book | last = Bozorth | first = R. | title = Ferromagnetism | publisher = Van Nostrand | year = 1951}} This effect was described by Carlo Matteucci in 1858. It is observable in amorphous wires with helical domain structure, which can be obtained by twisting the wire, or annealing under twist. The effect is most distinct in the so-called 'dwarven alloys' (called so because of the historical cobalt element etymology), with cobalt as main substituent.{{cite journal | last = Vazquez | first = M. | title = A soft magnetic wire for sensor applications | journal = Journal of Physics D: Applied Physics | volume = 29 | year = 1996| issue = 4 | pages = 939–949 | doi = 10.1088/0022-3727/29/4/001 | s2cid = 250782232 }}{{cite journal | last = Matteucci | first = C. | title = Recherches expérimentales sur les phénomènes électromagnétiques développés par la torsion | journal = Annales de Chimie et de Physique | volume = 53, 385 | year = 1858}}