Synthesis and Dielectric Properties of Li1-x+yTa1-x-3yTix+4yO3 M-Phase Solid Solutions

The synthesis, structure, and dielectric properties of the so-called M-phase solid solutions in the Li2O-Ta2O5TiO2 system were investigated. Although the range of stability of the tantalate phases is more limited compared with their niobate counterparts, they have identical structures based on intergrowths of LiTaO3type blocks separated by corundum type layers. The dielectric constants of the tantalate M-phases range from 68 to 52 and they all exhibit a negative temperature coefficient of capacitance. The temperature coefficient of the resonant frequency measured in the microwave region can be tuned to zero, and the system shows quite good quality factors with the highest value reaching a Q x f = 10500 at 6.7 GHz. Comments Copyright The American Ceramic Society. Reprinted from Journal of the American Ceramic Society, Volume 85, Issue 10, October 2002, pages 2487-2491. This journal article is available at ScholarlyCommons: http://repository.upenn.edu/mse_papers/45 Synthesis and Dielectric Properties of Li1 x yTa1 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 synthesis, structure, and dielectric properties of the socalled M-phase solid solutions in the Li2O–Ta2O5–TiO2 system were investigated. Although the range of stability of the tantalate phases is more limited compared with their niobate counterparts, they have identical structures based on intergrowths of LiTaO3-type blocks separated by corundum type layers. The dielectric constants of the tantalate M-phases range from 68 to 52 and they all exhibit a negative temperature coefficient of capacitance. The temperature coefficient of the resonant frequency measured in the microwave region can be tuned to zero, and the system shows quite good quality factors with the highest value reaching a Q f 10500 at 6.7 GHz.