Browsing by Author "Biswajit Jena"

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Dielectric and electrical properties measurement of BCTO and Co & V-doped BCTO synthesized via semi-wet route method
(Springer, 2023) Anup Kumar; Vinod Kumar; Manish Kumar Verma; Vishnu Shankar Rai; Dinesh Prajapati; Biswajit Jena; Dipendra Kumar Verma; Poonam Kumari; D. Tiwary; K.D. Mandal
Bi2/3Cu3Ti4O12 (BCTO) and Bi2/3Cu3Ti3.95Co0.025V0.025O12 (BCTCVO) Ceramic was synthesized by using a cost-effective novel semi-wet route method. The phase formation was confirmed by XRD analysis with traces of TiO2 and CuO phases of BCTO and BCTCVO ceramic. The average crystallite sizes of BCTO and BCTCVO ceramic were found to be 40.49 and 39.72 nm, respectively. XPS studies confirm the oxidation state of each elements in appropriate oxidation state. Elemental analysis was performed by EDS. It was observed that the maximum dielectric constant values of BCTO and BCTCVO ceramic were 3372 and 1663 at 523 K and at 1 kHz. The value of dielectric constant was observed very low at higher frequency. Tangent loss values of BCTO and BCTCVO ceramic were found 3.67 and 2.39 at 523 K and 1 kHz, respectively. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Effect of Niobium Doping on Dielectric, Electrical and Magnetic Properties of Bismuth Copper Titanium Oxide
(Pleiades Publishing, 2025) Biswajit Jena; Anup Kumar; Dinesh Prajapati; Rajni Baranwal; Shail Upadhyay; Narsingh Bahadur R. Singh; Dhanesh Tiwary; Kamdeo Mandal
Abstract: Bi2/3Cu3Ti4 –xNbxO12 (BCTNO) ceramics with compositions x = 0.05, 0.10, and 0.20 were fabricated through a semi-wet route and sintered at 1173 K for 8 h. A detailed study was conducted to investigate the impact of Nb substitution on the structural, dielectric, electrical, and magnetic characteristics of BCTO. The synthesized Bi2/3Cu3Ti4 –xNbxO12 (x = 0.05, 0.10, and 0.20) ceramics were designated as BCTNO-0.05, BCTNO-0.10, and BCTNO-0.20, respectively. X-ray diffraction (XRD) investigation highlights the presence of all characteristic peaks of the pure BCTO compound, confirming the development of a single phase with a well-defined crystal structure upon Nb doping up to a composition of 0.20. Furthermore, the lattice parameter of the synthesized compounds is found to decrease with increasing Nb concentration. Field emission scanning electron microscopy (FE-SEM) was employed to assess the microstructural alterations in the synthesized BCTNO ceramics. High resolution transmission electron microscopy (HR-TEM) images revealed that the BCTNO ceramics’ particle sizes varied from 189 to 191 nm. The valence states of various ions present in the Nb-doped BCTO ceramics were analysed utilizing X-ray photoelectron spectroscopy (XPS). The dielectric permittivity (εʹ) and tangent loss (tan δ) of BCTNO ceramics were found to decrease with rising frequency. Impedance analysis provided confirmation of thermally activated ionic conduction within the ceramics. The magnetization (M) vs. Magnetic field (H) studies revealed antiferromagnetic behaviour at low temperature, with indications of weak ferromagnetism. © Pleiades Publishing, Ltd. 2025.
Evolution of microstructure, dielectric, and electrical properties of Nd-doped BCTO synthesized via semi-wet route
(Springer Science and Business Media B.V., 2024) Dinesh Prajapati; Vishnu Shankar Rai; Biswajit Jena; Harish Verma; Atendra Kumar; N.B. Singh; K.D. Mandal
The Bi(2/3)-xNdxCu3Ti4O12 (BNCTO) ceramic with few selected concentrations (x = 0.05, 0.10, and 0.20) was fabricated through semi-wet route. The structural properties of synthesized compounds were examined using X-ray diffraction, followed by Rietveld refinement with a space group of Im-3. The crystallite size observed from X-ray diffraction was found in decreasing order with an increase in dopant concentration of Nd3+ ions in to BCTO ceramic. Scanning electron microscopy (SEM), energy-dispersive spectra (EDS), atomic force microscope (AFM), and X-photoelectron spectroscopy (XPS) were used to study the surface morphology, elemental compositions, surface roughness, and electronic state, respectively. Surprisingly, Nd doping can result in an exceptionally low dielectric loss (tan δ), with a minimum value of 0.05 at 1 kHz and 303 K for BNCTO-0.2. These findings show that Nd doping is more favorable to dielectric characteristics, introducing increased grain boundary resistance, activation energy, and lower conductivity. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.