Microwave dielectric properties of Ba5-xSrxTa4O15, Ba5NbxTa4-xO15 and Sr5NbxTa4−xO15 ceramics

The Ba5−xTa4SrxO15, Ba5NbxTa4−xO15 and Sr5NbxTa4−xO15 microwave dielectric ceramics were prepared by the conventional solid-state ceramic route. The dielectric properties of the ceramics were measured in the microwave frequency region. The ceramics have high dielectric constant, high quality factor (Qxf up to 37 350 GHz) and temperature coefficient of resonant frequencies in the range −60 to +78 ppm/°C depending on the value of x. The solid solutions show intermediate microwave dielectric properties in between that of the end members except for Sr5NbxTa4−xO15 which showed a lower value of the dielectric constant.