Low temperature properties of multiferroic BiFe0.9Cr0.1O3 compound

Single-phase BiFe0.9Cr0.1O3 compound with a grain size of ∼63∼63 nm was prepared by the sol–gel technique. A well-defined nonlinearity in the field dependences of magnetization as a result of the collapse of the space-modulated spin structure and the strong coupling between Fe3+ and Cr3+ superexchange interaction indicated a weak ferromagnetic character, and the observed significant deviation between the ZFC and FC curves suggested a spin-glass-like behavior at low temperatures. The low temperature dielectric constant showed two subtle anomalies at 50 and 230 K, which are related to the spin-glass behavior and magnetoelectric coupling. Moreover, the magnetoelectric coupling was estimated by determining the variation of the dielectric constant with applied magnetic field.

Research highlights
► Using a sol–gel approach can improve the chemical homogeneity of Cr in BiFeO3.
► Two subtle dielectric anomalies at 50 and 230 K were observed.
► Cr doping can improve the electric-magnetic coupling in BiFeO3.