Effect of antimony content on structural and dielectric properties of BaTi0.925[Yb0.5Nb0.5]0.075O3.

This work presents a fundamental investigation of structural, dielectric and vibrational properties of the doped of the classical BaTi_0.925(Yb_0.5Nb_0.5)_0.075O₃ (BTYN75) with a low amount of antimony Sb⁵⁺. The new lead-free ceramic BaTi_0.925[Yb_0.5(Nb_0.8Sb_0.2)_0.5]_0.075O₃ (BTYN75-Sb) was prepared using the solid-state reaction method at 1673 K for 4 h. This ceramic was characterized by X-ray diffraction (XRD), and the XRD pattern was fitted with the Rietveld's refinement. The structural analysis of BTYN75-Sb showed the coexistence of Pm3m-cubic symmetry (33%) and P4mm-tetragonal symmetry (67%) at room temperature (RT). The dielectric properties such as dielectric constant (ε′_r) and dielectric loss (tan δ) were determined. The dielectric constant was found to be ε′_r = 4109 at T_m = 290 K for 1 kHz. Typical relaxor behavior of BTYN75-Sb was observed and characterized with empirical parameters: ΔT_m = 4 K and γ = 1.84. Compared with the pure BTYN75, the low amount of antimony Sb⁵⁺ resulted in a slight reduction of the dielectric loss (tan δ < 0.042) over a wide temperature range [195–393 K]. The relaxor behavior and the structural properties of BTYN75-Sb were confirmed by Raman spectroscopic measurement. The relaxor BTYN75-Sb may be a promising candidate for several applications at RT and particularly for energy storage. [ABSTRACT FROM AUTHOR]