Effect of addition of strontium on the structure and microwave dielectric properties of BaNi2V2O8 ceramics

Ba 1-x Sr x Ni 2 V 2 O 8 (x = 0, 0.05, 0.1, 0.15) ceramics were fabricated utilizing the solid-state reaction methods. The XRD and structural refinement results demonstrated an increased presence of a new Ba 0.5 Sr 0.5 Ni 2 V 2 O 8 phase with higher Sr 2+ content. With a distinctive tetragonal structure, this new phase markedly differed from the hexagonal structure of BaNi 2 V 2 O 8 . Our analyses of molecular polarization, packing fraction, and distortion of the [NiO 6 ] octahedra revealed that the ε r and τ f of Ba 0.5 Sr 0.5 Ni 2 V 2 O 8 surpassed those of BaNi 2 V 2 O 8 , while its Q  ×  f value was lower. This explains the amplified ε r and τ f value, alongside the diminished Q  ×  f value of the ceramics. The introduction of Sr 2+ elevated the τ f value of the ceramics from − 49.5 ppm/°C to − 7.8 ppm/°C. The Ba 0.85 Sr 0.15 Ni 2 V 2 O 8 specimen, sintered at 950 °C for 4 h, exhibited the most superior microwave dielectric performance: ε r  = 12.7, Q  ×  f  = 34,200 GHz, τ f  =  − 7.8 ppm/°C. These outcomes underscore the promising practical potential of this ceramic.