Low-Temperature Sintering and Microwave Dielectric Properties of Bi(0.9)Ln(0.05)Li(0.05)V(0.9)Mo(0.1)O(4) (Ln = Sm, Nd and La) Ceramics

摘要

Microwave dielectric ceramics of Bi(0.9)Ln(0.05)Li(0.05)V(0.9)Mo(0.1)O(4) (Ln = Sm, Nd and La) with a low firing temperature were prepared via conventional solid-state reaction. The phases and microstructures of the ceramics were characterized by x-ray diffraction and scanning electron microscopy. The temperature coefficients of resonant frequency in the three compositions increased as sintering temperature increased. It is worth noting that a phase transition of the Bi(0.9)Ln(0.05)Li(0.05)V(0.9)Mo(0.1)O(4) (Ln = Sm, Nd and La) ceramics from a monoclinic to a tetragonal scheelite structure was found with an increase in sintering temperature. The densification temperatures of all compositions were below 700 degrees C. Excellent microwave dielectric properties were obtained for the Bi0.9Nd0.05Li0.05V0.9Mo0.1O4 ceramic sintered at 650 degrees C, with a dielectric constant of similar to 72.2, a quality factor of similar to 6467 GHz and a temperature coefficient of resonant frequency of similar to 2.6 ppm/degrees C. The Bi(0.9)Ln(0.05)Li(0.05)V(0.9)Mo(0.1)O(4) (Ln = Sm, Nd and La) ceramics are chemically compatible with both Ag and Cu powders at their sintering temperatures, and are thus a promising candidate for use in LTCC technology applications.