Structural evolution, sintering behavior and microwave dielectric properties of (1−x)Li3NbO4–xLiF (0≤x≤0.9)

• Published in: Journal of the European Ceramic Society Vol. 32; no. 6; pp. 1251 - 1259
• Main Authors: Bian, J.J., Wu, J.Y., Wang, L.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2012
• Subjects: Ceramics; Copper; Dielectric properties; LTCC; Microwaves; Phase transformations; Silver; Sintering; Solid solutions; Dielectric properties; LTCC
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2011.12.026

Sintering behavior, microstructure and microwave dielectric properties of (1−x)Li3NbO4–xLiF (0≤x≤0.9) ceramics have been studied in this paper. Continuous solid solution with rock salt structure formed across the entire compositional range. Phase transformed from ordered body-centered cubic phase to short range ordered face-centered cubic phase with the addition of LiF. The x>0.4 compositions could be densified at 850°C/2h. The optimized Q×f value for each composition increased with the increase of LiF content and saturated at about 75,000GHz when x≥0.15, whereas the optimized dielectric permittivity decreased with the increase of LiF content. All specimens exhibited negative τf value. The chemical compatibilities with copper (Cu) in the case of x=0.4 composition and silver (Ag) in the case of x=0.5 composition were also investigated, respectively. No chemical reaction has taken place between the matrix phase and Ag or Cu after sintering at 850°C/2h or 950°C/2h, respectively.