New Microwave Dielectric Ceramics BaLn2(MoO4)4 (Ln = Nd and Sm) with Low Loss

In the present work, a pure monoclinic phase of BaNd2(MoO4)(4) and BaSm2(MoO4)(4) was formed at 850 degrees C and 600 degrees C, respectively, via a solid-state reaction method. The ceramic samples were found to be well densified at 960 degrees C. Dense and homogeneous microstructures were revealed from the scanning electron microscopy. The microwave dielectric behaviors were studied as a function of sintering temperature and characterized in the temperature range 25 degrees C-120 degrees C. The best properties were obtained in ceramics sintered at 960 degrees C with a permittivity similar to 11.7, a Q x f value of 45 000 GHz and a temperature coefficient of frequency about -41 ppm/degrees C for BaNd2(MoO4)(4) ceramic at 9.9 GHz, and a permittivity similar to 11.8, a Q x f value of 20 000 GHz, and a temperature coefficient of frequency about -34 ppm/degrees C for BaSm2(MoO4)(4) ceramic at 9.7 GHz, respectively.