Effect of mono-dopants (Mg²⁺) and co-dopants (Mg²⁺, Zr⁴⁺) on the dielectric, ferroelectric and optical properties of BaTiO₃ ceramics

Abstract

In this work, BaTiO3, Ba(Mg0.01Ti0.99)O3, Ba(Mg0.015Ti0.985)O3, Ba(Mg0.02Ti0.98)O3 and Ba(Mg0.01Zr0.15Ti0.84)O3 ceramics have been prepared through conventional solid-state route to investigate the effects of Mg2+ and Zr4+ dopants as mono-substitution (only Mg2+) and co-substitution (Mg2+ and Zr4+) of B-site on the structural, electrical and optical properties of BaTiO3 ceramics. Exhibiting perovskite structure, Ba(Mg x Ti1−x)O3 ceramics revealed a decrement pattern of tetragonality with the increment of the concentration of MgO which was confirmed through Rietveld analysis. Morphological analysis of the sintered samples by scanning electron microscope showed a grain growth retardation phenomenon with Mg2+ addition. Releasing from this retardation process, Ba(Mg0.01Zr0.15Ti0.84)O3 showed a maximum dielectric constant of ∼1269.94 due to the enhanced domain wall motion and the confinement within the solubility limit of Mg2+. The ferroelectric characteristic of Ba(Mg x Ti1−x)O3 was sluggish due to the effects of grain size and its boundary. The optical band gap for BaTiO3 was found to be decreased from 3.55 eV to 3.06 eV with the addition Mg2+ content but for Ba(Mg0.01Zr0.15Ti0.84)O3, the value increased due to the Burstein-Moss effect. Again the FTIR analysis proved that no impurity phases were formed during the doping phenomenon, but in Ba(Mg x Ti1-x)O3 ceramics, a significant reduction of Ti-O bond strength was observed. However, BaTiO3, Ba(Mg0.01Ti0.99)O3, Ba(Mg0.015Ti0.985)O3 and Ba(Mg0.02Ti0.98)O3 ceramics had manifested P-E loop having lower remanent polarization and coercive field compared to Ba(Mg0.01Zr0.15Ti0.84)O3 ceramics with moderate electrical and optical properties. So, co-doping with Mg2+ and Zr4+ evidenced a favorable accession for the increment of the properties of BaTiO3 ceramics.

Structural, Electrical, Magnetic and Optical Properties of BaTi1-x(Ni1/2Nb1/2)xO3 Ceramics

“…Figure 5 shows the optical band gap energies of BTNNO ceramics. The optical band gap (E g ) is deduced via allowed direct inter-band transition between conduction and valence bands by Tauc's relation [28]:…”

Ho-Mn co-doping in barium titanate piezoceramics via sol-gel process followed by microwave and conventional heating

“…In the present study, the dielectric constant of the fabricated Ba 1−2x Ho 2x Ti 1−x Mn x O 3 (x = 0, 0.02, 0.04, and 0.06) piezoceramics has declined by increasing the frequency. Indeed, the dielectric constant of Ba 1−2x Ho 2x Ti 1−x Mn x O 3 (x = 0, 0.02, 0.04, and 0.06) piezoceramics is diminished as the frequency rose owing to the domain wall motion phenomena [53][54][55]. In the entire samples at low frequencies the domain walls in the fabricated Ba 1−2x Ho 2x Ti 1−x Mn x O 3 were moved effortlessly, aligning with the applied electric field, thus elevating the dielectric constant.…”

“…Conversely, at higher frequencies the electric field oscillated rapidly for the domain walls to keep pace. This impedes their motion and results in a lower dielectric constant [55,56].…”

Core–rim structure evolution and electric properties of Ca–Mg–Dy-co-doped BaTiO3 ceramics

“…15 Moreover, Mostari et al demonstrated that Mg 2+ doping in the Ti 4+ site could pin the oxygen vacancy (V O ) by forming the defect complex of Mg 00 Ti À V O and hence improved the reliability of dielectrics. 16 This effect was further enhanced by co-doping with other elements. [17][18][19] Yang et al and Gu et al reported 95BaTiO 3 -2MgO-2CaCO 3 -1Dy 2 O 3 ceramics with their improved breakdown strength, flattened e 0 -T characteristics, and excellent reliability.…”