Origin of Magnetic Dielectric Effect in Geometry Frustrated CuFe1−xMnxO2 Single Crystal

This work aimed to investigate low temperature magnetic dielectric behavior of CuFe 1− x Mn x O 2 ( x = 0, 0.01, 0.03, and 0.05). We also discussed the influence of different Mn 3+ -doped concentrations and analyzed the origin of magnetic dielectric coupling effect in CuFeO 2 . The obvious variation of dielectric constant with different magnetic fields and temperatures was observed. The critical magnetic fields and critical temperatures, where dielectric constant changed obviously, were closely related to ion-doped concentration. In the ferroelectric incommensurate (FEIC) phase, the dopant enhanced electric polarization by regulating magnetic order. Electric polarization was modified by external magnetic fields, which shows strong magnetoelectric coupling. Based on the special spin-frustrated configuration of the ‘‘Fe 3+ (Mn 3+ ) scalene triangular’’ in CuFe 1− x Mn x O 2 and the magnetostriction effect, a possible mechanism for the observed dielectric behavior was assumed. In the mechanism, the amplitudes, directions of oxygen ion shift, were mediated by both the applied magnetic field and Mn 3+ -doping level. Furthermore, the experimental results show that dielectric behavior of CuFe 1 −x Mn x O 2 has a close relationship with magnetic structure and geometry frustrated, which may open up a new vista for studies of magnetoelectric materials. Based on the experimental results, the effects of Mn 3+ doped on magnetic dielectric and possible mechanism diagrams were assumed.