Crystal structure, dielectric properties, and far-infrared reflectivity spectrum of a novel phosphate KBaPO4 ceramic at microwave frequency

A novel orthophosphate ceramic KBaPO4 was successfully synthesized via a solid-state reaction route and sur-veyed systematically in microwave properties. X-ray diffraction patterns confirmed that single phases were obtained of all ceramics sintered at 900-1100 degrees C. The dense ceramics with homogeneous microstructure was obtained when sintered at 1050 degrees C and revealed by density and microstructural studies. According to the chemical bond theory, P-O made a more significant contribution to the microwave properties of KBaPO4 ce-ramics. Infrared reflection spectrum results showed that the permittivity was related to the absorption of phonon oscillation. The optimum properties (epsilon r = 7.58, Qxf = 31,577 GHz, tau f =-13.3 ppm/degrees C) of KBaPO4 ceramics were obtained when sintered at 1050 degrees C.