Two novel ultralow temperature firing microwave dielectric ceramics LiMVO6 (MÂ =Â Mo, W) and their chemical compatibility with metal electrodes

Low temperature cofired ceramics technology (LTCC) has been widely studied and used in wireless communication because of their outstanding capability for device miniaturization and integration. However, many commercial microwave dielectric materials have high sintering temperatures that pose challenge for cofiring with inner electrodes. Herein, two brannerite vanadate LiMVO6 (M = Mo, W) ceramics with intrinsically low sintering temperatures were prepared. Dense and stable LiMVO6 (M = Mo, W) ceramics could obtained at 640 °C for LiMoVO6 and 700 °C for LiWVO6. Favorable microwave dielectric properties were also obtained with εr = 13.3, Q × f = 12,460 GHz, and τf = +101.0 ppm/°C for LiMoVO6 and εr = 11.5, Q × f = 13,260 GHz, and τf = +163.8 ppm/°C for LiWVO6. Moreover, the relationship between crystal structure and microwave dielectric properties was studied by means of packing fraction, bond valence, and octahedral distortion. Their chemical compatibility with the metal electrodes were confirmed.