Rutile-structured Ga_(0.5)B_(0.5)TiO_4 (B = Nb, Ta) microwave dielectric ceramics

摘要

Ga_(0.5)B_(0.5)TiO_4 (B = Nb, Ta) ceramics with Rutile structure were prepared through a mixed oxide solid state sintering route and characterized using X-ray diffraction and Raman spectroscopy. Structural analysis revealed a tetragonal (P42/mnm) symmetry for both the compounds. The sintered microstructure of Ga_(0.5)B_(0.5)TiO_4 (GNT) sample comprised faceted polygons while that of Ga_(0.5)B_(0.5)TiO_4 (GTT) comprised well connected irregular-shaped grains. Both the GNT and GTT samples exhibited promising relative permittivities (ε_r = 54.9 and 40.6) and quality factors (Q_u × f_o - 16,565 and 17,522 GHz) respectively; however, further investigations are needed to tune their temperature coefficient of resonant frequency (τ_f = 164.5 and 110.7 ppm/℃) through zero.