Comparative study of dielectric properties of MgNb₂O₆ prepared by molten salt and ceramic method

Abstract

Magnesium niobate (MgNb₂O₆) powder was synthesized by the conventional ceramic route as well as by the molten salt route using a eutectic mixture of NaCl-KCl as the salt and Mg(NO₃)₂·6H₂O and TiO₂ as the starting materials. Pure phase of MgNb₂O₆ could be obtained by the molten salt method at 1100°C. However, in ceramic method the pure phase of MgNb₂O₆ was obtained by heating at 1025°C for 20 h. On sintering at 1100°C the dielectric constant and dielectric loss of MgNb₂O₆ obtained by the molten salt method was found to be 19.5 and 0.004 at 100 kHz at room temperature. Lower values were obtained for these oxides prepared by the ceramic route, 16.6 and 0.000518, respectively. In both cases the dielectric constant was quite stable with frequency.