Relationship between structural and dielectric properties of Zn-substituted Ba5CaTi2-xZnxNb8O30 tetragonal tungsten bronze

Ba5CaTi2-xZnxNb8O30 ceramics (x = 0, 0.04, and 0.08) were synthesized by a conventional solid-state reaction method at 1300 degrees C for 6 hours. The effects of the Tian ratio on structural and dielectric properties were studied by changing the value of x. The pure phase formation of all prepared Ba5CaTi2-xZnxNb8O30 compositions was confirmed by X-ray diffraction. The refinement of the (XRD) data by the Rietveld method confirmed the tetragonal crystal structure with the space group P4bm at room temperature. Scanning electron microscopy (SEM) showed that the Ba5CaTi2-xZnxNb8O30 ceramics have good sinterability, low porosity and uniform distribution of grains of unequal size over the entire surface in all the samples. The average grain size is in the range of 1.3 to 1.6 mu m. The frequency-dependent dielectric properties were examined by complex impedance spectroscopy in the temperature range of SO degrees C to 420 degrees C where a structural phase transition was observed for all the samples.

Automated summary

Ba5CaTi2-xZnxNb8O30 ceramics with different x values were synthesized by solid-state reaction, and their structural and dielectric properties were studied. XRD and SEM analysis revealed the phase formation and microstructure characteristics of the ceramics, while complex impedance spectroscopy was used to investigate the frequency-dependent dielectric properties.