Crystalline Structure and Dielectric Properties of Li1+x-yNb1-x-3yTix+4yO3 M-Phase Solid Solutions

The structure and dielectric properties of the so-called M-phase solid solutions in the Li2O-Nb2O5-TiO2 system have been investigated. Detailed studies of the lattice parameters of these phases agree well with structure models based on intergrowths of LiNbO3 slabs with a titanium-rich corundum-type layer. The relative permittivity ranges from ~80 to ~55; microwave quality factors increase with the titanium content, reaching values of Q x f = 9000 at 6 GHz. The temperature coefficient of the resonant frequency changes sign within the solid solution region, thus permitting tunability to a zero value. All the compositions can be sintered to high density at temperatures ≤ 1100∘C. Comments Copyright The American Ceramic Society. Reprinted from Journal of the American Ceramic Society, Volume 85, Issue 3, March 2002, pages 573-578. This journal article is available at ScholarlyCommons: http://repository.upenn.edu/mse_papers/46 Crystalline Structure and Dielectric Properties of Li1 x yNb1 x 3yTix 4yO3 M-Phase Solid Solutions Albina Y. Borisevich and Peter K. Davies* Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6272 The structure and dielectric properties of the so-called M-phase solid solutions in the Li2O–Nb2O5–TiO2 system have been investigated. Detailed studies of the lattice parameters of these phases agree well with structure models based on intergrowths of LiNbO3 slabs with a titanium-rich corundum-type layer. The relative permittivity ranges from 80 to 55; microwave quality factors increase with the titanium content, reaching values of Q f 9000 at 6 GHz. The temperature coefficient of the resonant frequency changes sign within the solid solution region, thus permitting tunability to a zero value. All the compositions can be sintered to high density at temperatures <1100°C.