In this study, the doping of barium titanate was done by bismuth and strontium individually. The aim of the work was to emphasise the structural modifications that occur as a result of the incorporation of the dopants into the system of barium titanate. Sol-gel was the method of synthesis for the materials. The chemical formula used was Ba_1 - xY_xTiO_3 , where Y represents the two dopants bismuth and strontium and x was varied as 0, 0.05, 0.075, 0.10, and 0.15. The thermogravimetric analysis (TGA) curve, along with its first order derivative curve, indicated that the formation of the material and the stabilisation of the phase was around 900°C. Doping of barium titanate resulted in certain structural distortions, which have been discussed in terms of the defects introduced by the dopants in the system of barium titanate, the impact of their ionic radii on its crystal structure, and the varying values of the tolerance factor. These structural distortions were also experimentally supported by the X-ray diffraction (XRD) data obtained. Factors such as the ionic radii and oxidation state of the two dopants favour that when both are individually added to barium titanate, they are more inclined towards the A-site of the ABO3 perovskite structure of barium titanate.

In the present study, a series of bismuth-doped barium titanate (Ba1 − xBixTiO3, 0 ≤ x ≤ 0.15) ceramics were synthesized via the sol-gel method to explore a sustainable alternative to the conventional high-temperature solid-state technique. In comparison to the solid-state process, the sol-gel method adopted lower synthesis temperatures that minimized bismuth volatilization and resulted in a controlled crystallite growth and defect engineering at the nanoscale. An extensive structural, microstructural, optical, and electrical analyses revealed that the composition x = 0.05 achieved a favourable combination of properties, that included enhanced dielectric response, improved polarization behaviour, and a reduced optical band gap. As compared to the other synthesized compositions, x = 0.05 also exhibited the largest grain size, stable tetragonality, and a lower Curie temperature. Higher Bi concentrations showed either a suppressed dielectric performance or increased hysteresis losses, thus, highlighting the impact of compositional sensitivity of Bi-doped BaTiO3 ceramics prepared through sol-gel chemistry. The main novelty of this study lies in demonstrating that controlled low-concentration Bi doping facilitated by the sol-gel technique creates an optimal balance of lattice distortion, oxygen vacancy formation, and electronic structure modification which collectively impact the material’s optical, dielectric, and ferroelectric properties. Thus, the “low-dopant optimum” for the Ba1 − xBixTiO3 ceramics serves as an effective strategy for achieving improved energy storage and electro-optic characteristics.

This study reports the successful synthesis of holmium (Ho) and scandium (Sc) co-doped barium titanate Ba1-xHoxTi1-yScyO3 using sol-gel method. Samples of compositions of x = y = 0 (BT) and x = y = 0.05 (BHTS) have been synthesized. The crystallization, phase formation, and micro-structural changes in these samples have been studied with the help of thermogravimetric and X-ray diffraction analyses. The X-ray diffraction pattern confirmed well-crystallized tetragonal phases for the samples, with minute variations in peak positions. The average particle sizes of 95 nm in BT were found to be 59 nm in BHTS samples. This size decrease was supported by FE-SEM. The peak shift in BHTS was better observed in some of the vibrational frequencies in FTIR spectra. The incorporations and elemental composition of Ho and Sc was confirmed from the EDX analysis of the samples.

In this work, bismuth doped barium titanate was synthesized by the sol- gel method. The samples were prepared using the chemical formula, Ba1 - xBixTiO3 in which compositions corresponding to x = 0.05 and 0.15 i.e., Ba0.95Bi0.05TiO3 (BBT5) and Ba0.85Bi0.15TiO3 (BBT15), showed a relaxor - type behavior. The temperature and frequency dependent dielectric measurements, were made which clearly showed that the peak corresponding to the dielectric maxima shifted towards higher temperature as frequency is increased in both the cases. The calculated values of the index of relaxation and the broadening parameter from the linear fit of the experimental data which was plotted according to the modified Curie- Weiss law also supported this behavior. At 500 kHz, the index of relaxation was calculated as 1.61 and 1.43 for BBT5 and BBT15 respectively and the broadening parameter as 121.5 K and 96.9 K for BBT5 and BBT15 respectively. It was also concluded that lower concentration of bismuth (x = 0.05) showed a better performance as compared to that of the higher one.

Barium titanate (BaTiO3) was discovered during the Second World War, and since then, it has been a fundamental component in the development of advanced materials. It has special ferroelectric, piezoelectric, and dielectric qualities, thus, making it useful in a wide range of devices, from transducers to capacitors. The historical development of barium titanate is reviewed in this paper, with special attention given to the journey covered, i.e. right from the discovery to the current status, where it is being used as a crucial component of modern electronics. Doping of barium titanate is a major topic of discussion because different dopants can modify the material’s structural, electrical, and thermal characteristics. These modifications have enabled enhanced performance in specific applications, making barium titanate a versatile material. As compared to the lead-based materials, barium titanate stands out, since it is environmentally friendly and does not contain toxic elements, and its properties can be tuned through doping. This makes it a safer and sustainable choice, especially in the light of sustainable human development. The discussion of prospective advances and potential developments in the usage of doped barium titanate for emerging technologies concludes the paper. This is an in-depth review paper that covers all the major aspects related to barium titanate.

In the present work, pure and bismuth-doped barium titanates have been prepared using the sol-gel method. The chemical formula used for the synthesis of bi-doped barium titanate is Ba1-xBixTiO3, where the values of x have been chosen to be 0.00, 0.05, 0.075, 0.10, and 0.15. Barium acetate [Ba(CH3COO)](2). and titanium (IV) isopropoxide [Ti{ OCH(CH)(2)}(4)h i have been used as barium and titanium precursors, respectively. For bismuth doping, bismuth (III) nitrate pentahydrate [Bi(NO3)(3)center dot 5H(2)O. has been used. The paper discusses the preparation mechanism, tolerance factor, and the thermal characterization (TGA/DSC) results of pure and bi-doped barium titanate ceramics.

Abstract La doped lead titanate ceramic compositions Pb1−x La x TiO3 (PLT) for x = 0.0, 0.05, 0.1, 0.2 and 0.3 were synthesized by an acrylic acid modified sol-gel route. The microstructure, surface morphology, and optical properties of the resulting compositions were studied by using TGA, X-ray diffraction, Raman Spectroscopy, and UV–Vis spectroscopy. It was found that the acrylic acid acts as a strong gelling agent and the organic residue gets removed completely below 450 °C. Very smooth ceramic powders characterized by single perovskite phase were obtained. A reduction in the tetragonality ratio from 1.0698 to 1.0033 was observed with increasing La content from x = 0.0 to x = 0.3. The effect of reduced tetragonality was corroborated by the peak shift of soft modes in Raman spectra and approximately 2 cm−1 downshift of E(TO1) mode was observed for each atomic weight percent La addition in lead titanate. The average grain size was found decreasing marginally with the increasing La content in PLT. Using the UV–vis data, a slight but systematic increase in the direct absorption edge (band gap) from 3.155 eV to 3.234 eV was observed with increasing La content in the PLT compositions.

Ba 1-x Sr x TiO 3 (0.0 ≤ x ≤ 0.5) nanoceramics were synthesized via sol-gel route and the structural and electric properties of the resulting compositions were investigated. revealed A tetragonal crystal structures for x = 0.0 - 0.3 and a cubic structure for x = 0.5 compositions was revealed by X-ray diffraction. The smaller ionic radii of Sr ions resulted in the lowering of c/a ratio with increasing x and a tetragonal to cubic structural transformation was observed at around x = 0.4. The average crystallite size gradually decreased with increasing x from 0 to 0.5. This trend was visible in electron micrographs. The room temperature dielectric constant in these nanoceramics increases with increasing Sr and a maximum value of 1553 was observed for x =0.3. Curie temperature ( T c ) of 125 °C was obtained for x =0.0, which shifted toward lower temperature with increasing x value. The value of T c was observed as 100 and 75 °C for x = 0.1 and 0.3, respectively. The remnant polarization ( P r ), saturation polarization ( P s ), and coercive field ( E c ) decreased with increasing Sr concentration in BT due to the structural modifications. Value of P r decreases from 0.637 to 0.229 μC/cm 2 , P s decreases from 8.910 to 3.238 μC/cm 2 and E c decreases from 0.631 to 0.255 kV/cm with increasing x from 0 to 0.5.

In the present work, La-doped lead titanate ceramics (Pb1- (x) La (x) TiO3) (x = 0, 0.05, 0.10, 0.20 and 0.30 mol%) were synthesized using a modified sol-gel route. The crystallization process in resulting ceramics and the effect of La doping on their microstructure have shown that single crystalline phases were obtained above 490 degrees C. A systematic decrease in lattice tetragonality with La incorporation, as evaluated using tolerance factor was confirmed by X-ray diffractometer and energy dispersive analysis of X-ray measurements. Average crystallite size variation was correlated with the sintering and the La content.

Abstract In this work, structural, dielectric, ferroelectric, and ferromagnetic properties of BaTi1– x Fe x O3 (0 <x < 0.5) ceramics have been investigated. Structural investigations using X-ray diffraction reveal that Fe doping leads to the development of hexagonal phase as well as an increase in average grain size. The coexistence of tetragonal and hexagonal phases strongly depends upon the Fe concentration. The lattice strain and dislocation density are found decreasing with increasing Fe content from x = 0 to 0.5. A reduction in dielectric constant (from 1534 to 305) and Remnant polarization (from 1.105–0.015 μC/cm2) was observed with increasing x from 0 to 0.5. All Fe-doped samples exhibit ferromagnetic ordering with increasing saturation magnetization (Ms) 0.084 emu/g at x = 0.1–0.511 emu/g for x = 0.5 samples.

In this work, BaTi1-xFexO3 ceramics for x=0 to 0.5 were prepared using solid-state reaction technique and the structural, dielectric, ferroelectric, and ferromagnetic properties of resulting BaTi1-xFexO3 (0.0 ≤ x ≤ 0.5) compositions have been studied. Structural investigations using X-ray diffraction reveal that the Fe doping leads to the development of hexagonal phase as well as an increase in the average grain size. The coexistence of tetragonal and hexagonal phases strongly depends upon the Fe concentration. The lattice strain was found to decrease from 4.37 x 10−3 lin−2nm for x=0.0 to 2.31 x 10−3 lin−2nm for x=0.5 as the dislocation density decreases from 12.73 x 10−4 to 4.85 x 10−4 dislocations nm−2 with increasing Fe content from x=0.0 to 0.5. A reduction in the dielectric constant (from 1534 to 305) and Remnant polarization (from 1.105 μC/cm2 to 0.015 μC/cm2) was observed with increasing x from 0 to 0.5. All Fe doped samples exhibit ferromagnetic ordering with increasing saturation magnetization (Ms) 0.084 emu/g at x=0.1 to 0.511 emu/g for x=0.5 samples. The increase in Ms was found in corroboration with the hexagonal volume fraction in the samples.

BaTi 1-x Fe x O 3 compositions for x = 0.0 - 0.5 were successfully synthesized using solgel method and the structural, dielectric, ferroelectric, and ferromagnetic properties of these compositions were studied. X-Ray diffraction patterns revealed a tetragonal phase in x=0.0 composition which changed to the hexagonal phase in x = 0.4 and 0.5 compositions. The co-existence of tetragonal and hexagonal phases was observed in iron doped samples up to x= 0.3. The difference in ionic radii of Ti and Fe ions was responsible for changing c/a ratio. Average grain size was found gradually increasing with Fe content in these compositions and was also observed in SEM micrographs. The dielectric constant and tangent loss were found decreasing with Fe concentration. The values of remnant and saturation polarizations decreased whereas that of saturation magnetization increased with an increasing content of Fe in barium titanate.

Tetragonal lead titanate ceramics in nano particles forms were fabricated via sol-gel method. The gelation was achieved via mixing a solution of lead acetate, titanium isopropoxide in a solvent system of ethanol and acetylacetone. The gel was heated in a normal air oven at 120(0)C for 5 hours to get ceramic powder which was calcined at 600(0)C for two hours and cintered upto 1100(0)C. The calcined powder was characterized by X-ray diffraction XRD and SEM analysis. It has been observed that the particle size increases with temperature with a decrease in grain boundary area.

The free-standing g-C3N4 films were fabricated by thermal condensation of C2H4N4 at 600 °C in a low pressure of Ar atmosphere. The as-synthesized g-C3N4 films exhibited stable and strong photoluminescence emission centered around 455–460 nm.

We have prepared bamboo-shaped C–N nanotubes–polyethylene oxide (PEO) composite films by solution cast technique and investigated their structural/microstructural and electrical properties and developed a correlation between them. The formation of clean compartmentalized bamboo-shaped C–N nanotubes was confirmed by TEM. SEM investigations revealed a homogeneous dispersion of nanotubes in PEO matrix. Enhanced electrical conductivity was observed for the C–N nanotubes–PEO composites than bare PEO. The conductivity measurements on the C–N nanotubes–PEO composite films with ~20 wt % concentration of C–N nanotubes showed an increase of eight orders (~7.5 × 10−8 to 6.2 S cm−1) of magnitude in conductivity from bare PEO film. Raman spectra showed the stress-free nature of the composites and established the bonding of nanotubes with PEO, which resulted in the variation of Raman parameters. The Raman data of composites corroborate the findings of variation in electrical conductivity.

Raman spectra and fluorescence of BaTiO(3) and silica microspheres of different sizes have been studied. The observed whispering gallery modes (WGMs) have been assigned using theoretical simulations based on the Lorenz-Mie theory. The WGMs are found to have selective enhancements in the Raman spectra. The variations in the Raman spectra with the radial position of the excitation spot and excitation wavelength have been correlated with the morphology-dependent internal field distributions of the microspheres. The effect of a thin dye coating on the fluorescence and Raman spectra was studied, and a coating thickness of similar to 200 nm was estimated from the theoretical simulation of experimentally observed data based on the Aden and Kerker theory. Copyright (C) 2011 John Wiley & Sons, Ltd.

Superior battery materials LiAl x Co 1− x O 2 ( x = 0.0, 0.1, 0.3, 0.5, and 0.7) were synthesized using a solution-based route at various sintering temperatures (450–800 °C). In this communication, we report on the use of Raman spectroscopy to study effect of composition and sintering temperature on the resulting material. The phase evolutions in LiAl x Co 1− x O 2 compositions were studied using micro-Raman spectroscopy and a phase diagram is proposed based on the observations. For less Al content, the low-temperature phases of LiAl x Co 1− x O 2 showed Raman spectra corresponding to a monoclinic (space group C2/m) structure, while a low-temperature spinel (space group Fd3m) phase was observed for 50% or more Al in these compounds. All these compositions exhibited a layered hexagonal (space group R3m) structure when sintered above 700 °C. Raman spectra also revealed residual Co 3 O 4 in the low-temperature forms of LiCoO 2 and LiA1 0.01 Co 0.9 O 2 .