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 resonators in microwave technologies due to their adequate dielectric properties. These properties are mainly determined by the characteristics of the optical 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 highly ordered samples. In this work, we use Raman spectroscopy and X-ray diffraction to investigate hydrothermal Ba(Mg1.3Nb2.3)O-3-BMN-ceramics with different order degree. Spectroscopic and structural data showed sensitivity to the sample microstructural evolution during sintering. Besides, they allowed independent determination of the long range order degree of the materials. The complete Raman mode assignment for the disordered and ordered BMN structure is also presented. (C) 2001 Elsevier Science Ltd. All rights reserved.