Noncentrosymmetric Structure of LuFeO₃ in Metastable State

The crystal structure of metastable LuFeO 3 synthesized by containerless processing has been revealed to be a non-centrosymmetric structure (space group P 6 3 c m ) by analyzing the high-energy synchrotron-radiation powder-diffraction data using the maximum entropy method (MEM)/Rietveld method. The structural characteristics are found in the FeO 5 trigonal bipyramid distorted and tilted from the c -axis, which is cause by the hybridization of atomic orbitals between the O atom constituent of the polyhedron and the neighboring Lu atom. The spontaneous polarization expected from the polar structure is estimated at about 5 µC/cm 2 .