Calcium Manganese Vanadate Microwave Dielectric Ceramics with Ni2+ Partial Substitution for LTCC Applications

Here, Ca 5 Mn 4− x Ni x V 6 O 24 (CMNVO, x  = 0.00–0.08) ceramics are successfully prepared by the solid-phase reaction method, and the connection between the physical phase information, microscopic morphology, Raman spectroscopy, and microwave dielectric properties is explored. The experimental results show that Ni 2+ occupies the Mn 2+ sites without altering the crystal structure and is effectively solid-solvated into the lattice. The relative density reaches a maximum value of 95.9% when the temperature (Tem.) = 900°C and x  = 0.06. The trend of the dielectric constant ( ε r ) depends on the ionic polarization rate, and the quality factor ( Q×f values) are correlated with the microstructure and relative density. The maximum value of 43,800 GHz is reached at Tem. = 900°C and x  = 0.06, and the temperature coefficient of resonant frequency ( τ f values) is enhanced from −75 ppm/°C to −52 ppm/°C. The CMNVO ( x  = 0.06) ceramic obtains better microwave dielectric properties ( ε r  = 11.4, Q×f  = 43,800 GHz, and τ f  = −52 ppm/°C). This ceramic material is expected to be a candidate for low-temperature co-fired ceramic (LTCC) microwave devices.