Influence of light on the magneto­electric effect in Cr‐doped Bi12TiO20

Sillenites are well known and promising materials for holographic memory, because of a significant photorefractive effect. We have investigated Cr-doped BTO, pure BSO, and BGO single crystals for the magnetoelectric properties. Using light, an oxidation state of chromium dopant in sillenite Bi12TiO20 was manipulated that resulted in a sign change of the magnetoelectric effect. This change of sign correlates with different transformation properties of spinors corresponding to the states with integer and half-integer spins. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim