Structure, bond chemistry and enhanced microwave dielectric properties of La2−xYxMo2O9 ceramics with low sintering temperature.

Low-temperature sintered La 2−x Y x Mo 2 O 9 ceramics (x = 0–0.12) were synthesized by solid-state method. XRD analysis confirmed pure La 2 Mo 2 O 9 with a cubic structure (space group P 21 3). Sintering at 925 °C resulted in La 2 Mo 2 O 9 ceramic with favorable microwave dielectric properties: ε r = 17.8, Q × f = 24300 GHz, τ f = −35.1 ppm/°C. Notably, adding Y3+ greatly improved Q × f and τ f. Sintering La 1.88 Y 0.12 Mo 2 O 9 at 900 °C significantly enhanced microwave dielectric properties: ε r = 17.4, Q × f = 34100 GHz, τ f = −5.5 ppm/°C. ε r was primarily influenced by ionic polarizability, while Q × f correlated positively with packing fraction. Analysis based on P-V-L theory showed that increased ionicity, lattice energy, and bond energy led to higher ε r , Q × f , and τ f values. Raman spectroscopy revealed that most observed peaks were associated with Mo-O bond vibrations. These findings highlight La 2−x Y x Mo 2 O 9 ceramics as promising candidates for LTCC materials. [ABSTRACT FROM AUTHOR]