A novel low-loss CaLaNbWO8 microwave dielectric ceramic with a tetragonal structure

A novel CaLaNbWO8 (CLNWO) ceramic was prepared using traditional solid-state methods. The CLNWO ceramics that were sintered at 1440 degrees C displayed noteworthy dielectric properties, with epsilon r = 11.18, Q x f = 32,998 GHz, and tau f =-8.1 ppm/degrees C. The trends in epsilon r and Q x f were indirectly reflected through the Raman shift and FWHM in Raman spectroscopy. Through bond valence analysis, it was determined that Ca2+ and La3+ have significant compression effects in CLNWO ceramics, and the alpha c was less than alpha theo . The microstructure of the ceramics was further studied by scanning electron microscopy (SEM). It was found that the grains were highly dense, the grain boundaries were obvious and there were no cracks at the optimum temperature. This discrepancy resulted in the epsilon r of CLNWO ceramics being less than epsilon theo . According to Phillips-Vechten-Levine (P-V-L) theory, the W-O bond primarily determined tau f , and Q x f , whereas epsilon r was noticeably influenced by the La-O bond.