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Polycrystalline Lu-doped YFeO3 samples with perovskite structure were synthesized by solid-state reaction. Powder X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray analysis manifest the high quality of the samples. Room temperature 57Fe Mössbauer spectra indicate that only the Fe3+ exists in the samples, which excludes the formation of multiple valence of Fe. The large effective magnetic moments of Fe3+ obtained from the temperature dependence of magnetization data can be explained in terms of the formation of ferromagnetic clusters. Field-dependent magnetization reveals that all the samples show weak ferromagnetic property due to the small canting of the Fe3+ moments. The field-induced spin-reorientation was detected on YFeO3 and was gradually suppressed by Lu3+ doping. Polarization hysteresis loops of Y1−xLuxFeO3 (0 ≤ x ≤ 1) were observed at room temperature. Our results suggest that the multiferroic properties may exist in the Y1−xLuxFeO3 (0 ≤ x ≤ 1) ceramics.

We report the observation of current-induced abrupt transition from a metallic to an insulating state in a bilayered manganite La 1.2 Sr 1.8 Mn 2 O 7 single crystal. A colossal electroresistance effect ͓͑50 mA͒ − ͑1 mA͔͒ / ͑50 mA͒ = 93% is found at 120 K. Moreover, the current-induced transition is very sensitive to external magnetic fields. At the measuring current of 50 mA a low-field colossal magnetoresistance effect, ͓͑H͒ − ͑0͔͒ / ͑0͒ = −86%, occurs at H = 500 Oe. This low-field magnetoresistance effect can be repeatedly modulated by external magnetic field. We interpret these phenomena as the consequence of the percolative conduction and local Joule thermal effect.

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9 . -The new title compound is synthesized by solid state reaction of a stoichiometric mixture of Nd2O3, BaCO3, and MnCO3 (1300°C, 12 h). TEM reveals a chemical phase separation phenomenon leading to the coexistence of the perfect 12R-type structure with an average chemical composition of Ba4NdMn3O12 (space group R3m) and the Nd-rich modulated superstructure. In the 12R-type structure, the Nd cations are located in the corner-sharing octahedra, whereas the Mn cations are located in the face-sharing octahedra, leading to a remarkable cation ordering. -(YANG, H.; TANG, Y. K.; YAO, L. D.; ZHANG, W.; LI, Q. A.; LI, F. Y.; JIN, C. Q.; YU*, R. C.; J.

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Using nanoparticles of CeO 2 and ZrO 2 prepared by a chemical precipitation method as starting materials, single-phase cubic Ce 0.5 Zr 0.5 O 2 solid solution (c-Ce 0.5 Zr 0.5 O 2 ) has been synthesized under 3.1 GPa at 1073 K for the first time. The EPR and XPS measurements show that there exists no Ce 3+ in it and that the Ce 4+ has not been reduced to Ce 3+ after annealing. The transport mechanism is ionic for the c-Ce 0.5 Zr 0.5 O 2 . The bulk conductivity is the same as that of CeO 2 , but smaller than that of Y 2 O 3 -stabilized ZrO 2 .

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