Evidence of a New Current-Induced Magnetoelectric Effect in a Toroidal Magnetic Ordered State of UNi 4 B

Magnetization measurements under direct electric currents were performed for toroidal magnetic ordered state of UNi₄B to test a recent theoretical prediction of current-induced magnetization in a metallic system lacking local inversion symmetry.We found that each of the electric currents parallel to [21̄1̄0] and [$0001$] in the hexagonal 4-index notation induces uniform magnetization in the direction of [011̄0].The observed behavior of the induced magnetization is essentially consistent with the theoretical prediction; however it also shows an inconsistency suggesting that the antiferromagnetic state of UNi₄B could not simply be regarded as a uniform toroidal order in the ideal honeycomb layered structure.