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The double peroskite Lu 2 NiMnO 6 was synthesized by a facile hydrothermal method. X-ray power diffraction (XRD) analysis shows it adopts monoclinic structure with space group P2 1 /n , indicating an ordered arrangement at B sites. Valence states analysis done by XPS shows Ni 2+ /Mn 4+ configuration. Raman spectrum reveals an ordered structure in the sample, in agreement with the XRD results. The degree of ordering was greatly enhanced after the sample was annealed at 873 K. Magnetism of the as-grown and annealed samples was analyzed using DC and AC magnetization, as well as Magnetization-Hysteresis. Dielectric anomaly independent on frequency was observed close to the magnetic ordering temperature, indicating the possibility of ferroelectricity and further magnetoelectric coupling. [ABSTRACT FROM AUTHOR]

The perovskite orthoferrite SmFeO 3 was synthesized by the hydrothermal method. The Néel temperature of this material was found to be 655 K by temperature-dependent magnetization measurements. Magnetic field-dependent magnetization of the material at 300 K revealed typical weak ferromagnetic behaviour. Dielectric analysis showed a ferroelectric phase transition at 480 K. The structural and magnetic properties of SmFeO 3 were also characterized using Mössbauer spectra, which also confirmed this structural transition. The remanent polarization determined by the positive-up-negative-down (PUND) method was approximately 0.012 μC/cm 2 at 173 K. Therefore, the results presented here indicate that SmFeO 3 is multiferroic at temperatures above room temperature. Our analysis shows that the material's non-centrosymmetric Pna2 1 structure is likely to be responsible for the ferroelectricy in SmFeO 3 rather than the Pbnm structure or the magnetic structure. [ABSTRACT FROM AUTHOR]