Raman scattering and X-ray diffraction investigations on hydrothermal barium magnesium niobate ceramics

Ba(B'B-1.3"(2.3))O-3 perovskites are important ceramic materials used as re sonators in microwave technologies due to their adequate dielectric propert ies. These properties are mainly determined by the characteristics of the o ptical polar phonons of the material. A few spectroscopic investigations of lattice vibrations in Ba(B'B-1.3"(2.3))O-3 ceramics were realized in highl y ordered samples. In this work, we use Raman spectroscopy and X-ray diffra ction to investigate hydrothermal Ba(Mg1.3Nb2.3)O-3-BMN-ceramics with diffe rent order degree. Spectroscopic and structural data showed sensitivity to the sample microstructural evolution during sintering. Besides, they allowe d independent determination of the long range order degree of the materials . The complete Raman mode assignment for the disordered and ordered BMN str ucture is also presented. (C) 2001 Elsevier Science Ltd. All rights reserve d.