Microwave dielectric properties of Ca(Li1/4Nb3/4)O3-CaTiO3 ceramic systems

초록

The microwave dielectric properties of Ca(Li1/4Nb3/4)O-3-CaTiO3 ceramics have been investigated with regard to calcination temperature and the amount of CaTiO3 additive. Ca(Li1/4Nb3/4)03 ceramics with an orthorhombic crystal structure can be synthesized by the conventional mixed oxide method by calcining at 750 degrees C and sintering at 1275 degrees C. The dielectric constant (epsilon(r)), quality factor (Q x f(0)) and temperature coefficient of resonant frequency (tau(f)) for Ca(Li1/4Nb3/4)O-3 ceramics are 26, 13,000 GHz and -49 +/- 2 ppm/degrees C, respectively. With increase in the CaTiO3 content, epsilon(r) and tau(f) are increased and the quality factor decreased due to the solid-solution formation between Ca(Li1/4Nb3/4)03 and CaTiO3. The 0.7Ca(Li1/4Nb3/4)O-3-0.3CaTiO(3) ceramic exhibits 8, of 44, quality factor (Q x f(0)) of 12,000 GHz and tau f of -9 +/- 1 ppm/degrees C. (c) 2005 Elsevier Ltd. All rights reserved.

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