Multiferroicity in Quasi-One-Dimensional Compound Ca₃NiMnO₆

The magnetic structure of the one-dimensional (1D) compounds A3MXO6 (where A is Ca or Sr, M and X are transition metal cations) can be tuned from collinear to spiral by merely changing the identity of the M and X atoms constituting the 1D chains. This suggests the prospect of realizing ferroelectricity that is induced by different types of magnetic order. To date, magnetism-driven ferroelectricity in these 1D compounds has only been discovered in Ca3CoMnO6 with a collinear magnetic structure, whereas other magnetic structures such as spin spirals have been much less discussed. Here, the magnetoelectric effect in 1D Ca3NiMnO6 with a spiral magnetic structure is investigated. The presence of magnetoelectric coupling in the sample is evidenced by changes in capacitance of up to 1.5% in an applied magnetic field of 8 T at a temperature of 5 K. These results highlight the relation between magnetic and electric order in 1D compounds with a spiral magnetic structure and provide more insight into magnetoelectric coupling mechanisms in 1D compounds in general.