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°C and 600°C, respectively, via a solid‐state reaction method. The ceramic samples were found to be well densified at 960°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°C–120°C. The best properties were obtained in ceramics sintered at 960°C with a permittivity ~11.7, a Q × f value of 45 000 GHz and a temperature coefficient of frequency about −41 ppm/°C for BaNd2(MoO4)4 ceramic at 9.9 GHz, and a permittivity ~11.8, a Q × f value of 20 000 GHz, and a temperature coefficient of frequency about −34 ppm/°C for BaSm2(MoO4)4 ceramic at 9.7 GHz, respectively.