Study on the effect of Bi dopant on the structural and optical properties of BaTiO₃ nanoceramics synthesized via sol-gel method

Abstract

In this study the preparation of pure and Bismuth (Bi) doped barium titanate (BaTiO3) nanoceramics by sol-gel process is reported. The structural and optical properties of the samples were investigated using X-ray diffraction (XRD) and UV-visible spectroscopy. XRD results show that the samples are crystallized in the pure perovskite structure when calcined at relatively low temperature (800 °C) for 3 h, without the presence of secondary phases. Both Bi doping (1%, 2%) decrease the lattice parameters, tetragonality and the crystallite size. The decrease of their sizes can be explained by the replacement of large ionic radii of Ba2+ (1.35Å) ion by smaller ionic radii Bi3+ (1.03 Å) ion. A close investigation of the results shows that BT is a tetragonal-phase ferroelectric. The band gap of the Bi-doped BaTiO3 nanopowders is lower compared to that of pure BaTiO3, as determined from the analysis of UV absorbance spectra.

Giant effect on structural, magnetic, electrical, and optical properties of lead-free Ba0.6Sr0.4Ti1-xAlxO3 ceramics via Sr and Al Co-doping engineering

“…Furthermore, the band gap energy variations may also be confirmed by lattice parameters and the changes in electrical structure. The result is compatible with XRD research, which shows that adding Al dopant increases particle size [110]. Besides, the density, grain size, and oxygen deficit may all have a favorable influence on optical characteristics.…”

Functionality and Activity of Sol–Gel-Prepared Co and Fe co-Doped Lead-Free BTO for Thermo-Optical Applications

“…The lattice parameters of BTO are in good agreement with the values reported in the literature and with our recently published results. 4 , 12 , 45 , 46 Table 1 shows that the lattice constant a remains almost constant with the Fe and Co doping elements, while the lattice constant c decreases, which is due to the incorporation of Fe 3+ and Co 2+ into the sites of Ba 2+ (1.35 Å) and Ti 4+ (0.60 Å), which is directly due to the difference in the ionic radius of the presented ions (Fe 3+ , Co 2+ , Ba 2+ , and Ti 4+ ). Further, the c/a ratio of the tetragonal lattice system decreased from 1.010 (BTO) to 1.005 for BCTF.…”

“…In the last decades, extensive research has been carried out to synthesize a doped BTO material with controlled particle size distribution and high purity. As a result, numerous techniques have been used to prepare pure and doped BTO materials, including the sol–gel method, , autocombustion route, solid-state reaction, and hydrothermal reaction, to enhance its structural, electrical, optical, thermal, and mechanical properties . Among all these methods, sol–gel is considered an effective technique that allows the production of materials with high purity at the nanoscale, better control of stoichiometry, minimum particle agglomeration, homogeneity at a microscopic level, reduction in the sintering temperature, and more uniform powders …”

Synthesis of Ba1−xSrxTiO3 (x = 0–0.3) Ceramic Powders via Sol‐Gel Method: Structural, Microstructure, Thermal Conductivity, and Compressive Strength Properties

“…The pure and Sr-modified BaTiO 3 powders were prepared through the sol-gel method [22,23] using barium acetate trihydrate (Ba (CH 3 CO 2 ) 2 .3H 2 O) (99,9% purity), strontium acetate (C 4 H 6 O 4 Sr) (99% purity), and Titanium alkoxide Ti [OCH(CH 3 ) 2 ] 4 (97%, purity) as precursors, Lactic acid (CH 3 CH (OH) CO 2 H) as a peptizing agent, acetic acid to dissolve barium and strontium acetates and distilled water as a solvent.…”