Impact of Ca2+ substitution on the dielectric and ferroelectric behavior of BaTi0.95Sn0.05O3: A study of electron density distribution

In this study, lead-free Ba 1- x Ca x Ti 0.95 Sn 0.05 O 3 ( x = 0.0, 0.05, 0.10, 0.15, and 0.20) ceramics were prepared using the conventional solid-state sintering route. The effects of Ca 2+ doping at the A-site on the structural, dielectric , ferroelectric , and electrostrain properties were investigated. XRD , Rietveld refinement , and Raman spectra results revealed the coexistence of orthorhombic ( O ) and tetragonal ( T ) phases within the composition range of 0.0 ≤ x ≤ 0.10. The covalent bond between Ti and O atoms was confirmed through charge density analysis using refined structure factors. The Curie temperature ( T C ) showed an increasing trend from 71.1 °C to 91.5 °C with the addition of Ca 2+ content. The best electrical properties were observed at x = 0.05, with values of P m ⁓ 16.56 μC/cm 2 , P r ⁓ 10.78 μC/cm 2 , E C ⁓ 3.02 kV/cm, S max = 0.096 %, and d 33 ∗ = 355 p.m./V. The compositions exhibited improved ferroelectric and electrostrain properties for x ranging from 0.0 to 0.05, making them promising candidates for lead-free piezoelectric ceramics. • Lead-free Ba 1- x Ca x Ti 0.95 Sn 0.05 O 3 ceramics were prepared using the conventional solid-state sintering route. • XRD, Raman spectroscopy, and temperature-dependent dielectric analysis revealed the coexistence of two phases (orthorhombic ( O ) and tetragonal ( T )) in the range of x = 0.0 to 0.10. • To correlate the electrical properties with the electron density distribution at the lattice sites of BaTi 0.95 Sn 0.05 O 3 ceramics with Ca 2+ substitution. • The best electrical properties were observed at x = 0.05, with values of P m ⁓ 16.56 μC/cm 2 , P r ⁓ 10.78 μC/cm 2 , E C ⁓ 3.02 kV/cm, S max = 0.096 % and d 33 ∗ = 355 p.m./V.