Sintering behavior, microwave dielectric properties, and chemical bond features of novel low-permittivity Cu3(PO4)2 ceramic with low-loss

A novel Cu-3(PO4)(2) as microwave dielectrics was investigated in terms of sintering behavior and microwave dielectric properties. Samples were prepared using the solid-state sintering method. XRD data indicates that the Cu-3(PO4)(2) ceramic possesses a triclinic structure and belongs to the space group of P-1 (No. 2). Its microstructure was observed using a scanning electron microscope. Results confirmed that a dense ceramic was obtained at 900 degrees C. The permittivity and quality factor of Cu-3(PO4)(2) ceramics possess distinct density-dependent properties. A low permittivity (epsilon(r)) of 7.33 coupled with Q x f of 86,753 GHz (at 10.18 GHz) and tau(f) of 33.80 ppm/degrees C was obtained in the dense Cu-3(PO4)(2) ceramic at 900 degrees C for 2 h. The Cu-3(PO4)(2) ceramic exhibits well compatibility with Ag. Accordingly, it is a promising candidate for microwave materials with low permittivity and low loss. The microwave dielectric properties were discussed from the viewpoint of chemical bond theory. The qualified chemical bond features indicate the major contributions of P-O chemical bonds in the microwave dielectric response of the Cu-3(PO4)(2) ceramic.