Crystal structure and chemical bond characteristics for Li2Zn2(MoO4)3 microwave dielectric ceramics for ULTCC application

Li2Zn2(MoO4)(3) (LZMO) ceramics were prepared via solid-state method. XRD analysis showed LZMO phase had an orthorhombic structure with Pnma space group, representing the only crystalline phase. Ceramic sintered at 600 degrees C exhibited high relative density (96.2 %) and dense microstructure, demonstrating optimal microwave dielectric properties: epsilon(r) = 10.38, Q x f = 69,400 GHz, and tau(f) = -72.81 ppm/degrees C. Further investigations revealed close correlation between epsilon(r) and polarizability, emphasizing greater influence of relative density on Q x f than packing fraction. Increase in distortion of [Li/ZnO6] octahedra resulted in deterioration of ceramics' tau(f). Computation based on P-V-L theory revealed significant impact of ionicity, lattice energy, and bond energy on epsilon(r), Q x f, and tau(f), with Mo-O bonding dominating ceramics' microwave dielectric properties. Raman spectroscopy analysis showed majority of Raman bands attributed to vibrational modes of Mo-O bonds. LZMO ceramics have great potential in ULTCC field.