Room-temperature multiferroic characteristics and unique vortex domain structures of h-Yb1-xInxFeO3 solid solutions

Hexagonal rare-earth ferrites (h-RFeO3) have attracted much scientific attention due to their room-temperature multiferroicity. However, it is still a hard job to obtain h-RFeO3 bulk materials because of the meta-stability of such hexagonal phase, and the evaluation of room-temperature ferroelectric and magnetoelectric characteristics in such materials is also a challengeable issue. In the present work, Yb1-xInxFeO3 ceramics with the stable hexagonal structure were obtained by introducing chemical pressure, where the unique ferroelectric domain structures of sixfold vortex combined with tenfold vortex with a typical size of similar to 400 nm were determined. Symmetry of the present system evolved from centrosymmetric orthorhombic Pbnm (x = 0-0.4) to non-centrosymmetric hexagonal P6(3)cm (x = 0.5 and 0.6) with a ferroelectric polarization up to 3.2 mu C/cm(2), and finally to centrosymmetric hexagonal P6(3)/mmc (x = 0.7 and 0.8). The Curie point decreased monotonically from 723 K to a temperature below room temperature with increasing x, and the antiferromagnetic phase transition above room temperature was determined for all compositions. Meanwhile, a large linear magnetoelectric coefficient (alpha(ME)) up to 0.96 mV/cm Oe was obtained at room temperature, and this indicated the great application potential for magnetoelectric devices.