Phase equilibria, and electrical properties of compounds in the system MgO-La2O3-TiO2 at 1200 degrees C

Phase relations, the existence of compounds and their electrical properties in the system MgO-La2O3-TiO2 have been investigated by means of solid stat e synthesis, X-ray diffraction analysis and a.c. impedance technique. Three compounds, MgLa10Ti7O30 (hexagonal, a=0.55642 nm, c=1.09916 nm, Z=1), MgLa 6Ti4O18 (hexagonal, a=0.5566 nm, c=3.9692 nm, Z=3) and the new compound MgL a2TiO6 (orthorhombic a=0.56511 nm, b=0.76902 nm, c=0.55125 nm, V=2.395 nm(3 ), Z=2) were found in the system. The conductivity and dielectric constants of the pure phases were also measured. It was found that the epsilon' valu e of MgTi2O5 is 80, whereas the epsilon' value of the other phases are less than 63. (C) 1999 Elsevier Science S.A. All rights reserved.