Gd₂Zr₃(MoO₄)₉ microwave dielectric ceramics with trigonal structure for LTCC application

Abstract

Gd2Zr3(MoO4)9 is a double trigonal molybdate crystallized in the space group R3¯c. The optimal microwave dielectric properties were achieved via solid‐state reaction at 725°C for Gd2Zr3(MoO4)9 ceramics: εr = 11.17, Q × f = 57 460 GHz, τf = −31.91 ppm/°C. The three‐dimensional framework type structure is formed by mixed MoO4 tetrahedron and ZrO6/GdO9 polyhedron. The analysis based on complex chemical bond theory shows that the Mo–O bonds account for majority contribution to controlling microwave dielectric properties. The MoO4 tetrahedron and ZrO6 octahedron stabilize the crystal structure by strong binding ability. As it was shown by Raman spectroscopy, the Raman‐active vibrations primarily originate from MoO4 tetrahedron, similarly to molybdate analogies.

Low-temperature sintering, dielectric performance, and far-IR reflectivity spectrum of a lightweight NaCaVO4 with good chemical compatibility with silver

“…The latter is a more desirable technique compared to the first one due to the simple processing and comprehensive dielectric properties. The intensively explored low-sintering materials mainly include Li2O, Bi2O3, TeO2, MoO3, WO3, and V2O5 [13][14][15][16][17][18][19]. Recently, vanadates have attracted considerable attention for their potential applications in LTCC in consideration of their low molten point and outstanding microwave dielectric properties [20][21][22][23][24].…”