Crystal structure

Dielectric resonator antenna

Ceramic

Composite material

Optoelectronics

Analytical Chemistry (journal)

Crystallography

Monoclinic crystal system

Dielectric

Temperature coefficient

Tetragonal crystal system

Chemistry

Materials science

Chromatography

Chemistry of Materials

Phase transition–structure–dielectric properties in microwave band correlations were determined for the (Sm1–xCax) (Nb1–xMox)O4 (SNCMo@x) system. X-ray and Raman analyses along with selected-area electron diffraction indicated that SNCMo@x (0.15 ≤ x < 0.375) ceramics crystallize in the I2/a space group (monoclinic fergusonite), whereas the I41/a space group (tetragonal scheelite) best describes SNCMo@x (0.375 ≤ x ≤ 0.7), suggesting that the increased ionic radius of the A-site effectively contributed to the ferroelastic phase transition and ensures the stability of the scheelite phase. The SNCMo@x ceramic materials exhibit composition-dependent permittivity (εr) with a distribution between 12.0 and 17.7. The distortion and deformation of the [BO] polyhedra should be responsible for the shift from negative to positive temperature coefficient of resonant frequency (TCF) and the irregular behavior of the quality factor (Q × f). An optimum microwave dielectric performance was achieved for SNCMo@0.18 (εr ∼ 17.1, Q...

Design and Fabrication of a Satellite Communication Dielectric Resonator Antenna with Novel Low Loss and Temperature-Stabilized (Sm1–xCax) (Nb1–xMox)O4 (x = 0.15–0.7) Microwave Ceramics