A Rare Ferroelectric Material

The solid-state reaction method was employed to synthesize the ceramic samples of fresnoite (barium titanium silicate mineral) doped with calcium (Ca 2+ ) and having general formula Ba 2-x Ca x TiSi 2 O 8 (BCTS), utilizing high purity oxides and carbonates. X-ray diffraction technique and scanning electron microscopic (SEM) technique were used to explore the phase pure crystallization and structural characteristics of compounds. Furthermore, the analysis of obtained PXRD data was done via Rietveld refinement using the space group P4bm . The lattice constants and other structural parameters computed using the Rietveld refinement are consistent with the preceding study thus far, as evidenced by a good agreement between observed and computed interplanar d-spacing. The Raman spectra of tetragonal Ba 2-x Ca x TiSi 2 O 8 ceramics were measured at 300 K, revealing distinct modes. Detailed investigations were conducted to analyze the changes in Raman modes corresponding to varying concentrations of Ca 2+ substitution. The surface morphology and grain bonding in the synthesized compounds were performed using scanning electron microscopy. To determine the activation energies of the compounds, their dc electrical conductivities were measured. The pristine compound exhibited significantly high activation energy (4.74 eV), which decreased as the doping concentrations increased. The dielectric constant and dissipation factor with varying frequency and temperature were studied and it has been established that Ba 2-x Ca x TiSi 2 O 8 is insulating at room temperature (300 K). The impact of Ca doping on heat flow, specific heat, and other thermal parameters was investigated using modulated differential scanning calorimetry (MDSC).