Crystals of solid solutions Bi1 _~R~FeO3, where R= La, Dy, Gd, were obtained with x~0.7. Solid solutions of the stated rare earths, as xis increased from 0 to 0.7, have one and the same sequence of five crystal structures (rhombohedral~triclinic C{, orthorhombic D~,orthorhombic Dl, orthorhombic Ct). The ferroelectric-paraelectric transition occurs in rhombohedral and triclinic crystals at T= 810-560°C.The high temperature modifications are orthorhombic and cubic. The orthorhombic structurẽ holds up to 1180°C.The ferroelectric domain structure was distinguished in all types of crystals. No magnetoelectric effect (MEE) was detected in the orthorhombic crystals with the D2 (222) symmetry class. But the mm2 crystals were found to have both quadratic and linear MEE. The value of the quadratic effect is considerably smaller than that ofthe linear one. Magnetoelectric hysteresis takes place in the crystals. The tensorial properties of the obtained crystals are analyzed from the viewpoint of crystal symmetry.

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Polycrystalline material obtained from the ground single crystal of BiFeO3 reported as not having the superstructure, shows the superstructure reflections in neutron diffraction pattern. Tle determined magnetic moment of antiferromagnetically ordered Fe 3+ ions is µFe = (3.70±0.03)μB at 293 K.

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