Photomagnetism

Not to be confused with Photoelectric effect.
The energy diagram of the transitions between the ground state and the magnetic state. Solid arrows represent absorption of photons and dashed arrows represent non radiative processes

Photomagnetism (photomagnetic effect) is the effect in which a material acquires (and in some cases loses) its ferromagnetic properties in response to light. The current model for this phenomenon is a light-induced electron transfer, accompanied by the reversal of the spin direction of an electron. This leads to an increase in spin concentration, causing the magnetic transition.[1] Currently the effect is only observed to persist (for any significant time) at very low temperature. But at temperatures such as 5K, the effect may persist for several days.[1]

  1. ^ a b Pejaković, Dušan A.; Manson, Jamie L.; Miller, Joel S.; Epstein, Arthur J. (2000). "Photoinduced Magnetism, Dynamics, and Cluster Glass Behavior of a Molecule-Based Magnet". Physical Review Letters. 85 (9): 1994–1997. Bibcode:2000PhRvL..85.1994P. doi:10.1103/PhysRevLett.85.1994. ISSN 0031-9007. PMID 10970666.