Dr Dinesh Uthra | Guru Ghasidas University (original) (raw)

Uploads

Papers by Dr Dinesh Uthra

Chhattisgarh Journal of Science and Technology, 2018

The site-doping strategy of barium titanate (BaTiO3) is a promising way to develop new lead-free ... more The site-doping strategy of barium titanate (BaTiO3) is a promising way to develop new lead-free materials for energy with enhanced
dielectric and piezoelectric properties. A novel strategy to elaborated pure and substituted ferroelectric powders at low temperature is proposed.
Perovskite BaTiO3 (BT) and cobalt/chromium substituted barium titanate (Ba0.9R0.1TiO3 (R=Co and Cr)) have been prepared. The structural
properties investigated by various techniques viz. XRD and Raman analysis. The XRD analysis confirms the formation of single phase materials
and tetragonal structure of both pure and modified barium titanate compositions. Raman spectra has also confirms the tetragonality of the
samples. The present study may provide a new strategy to design lead-free ferroelectric materials with enhanced structure and microstructure
properties at very low temperature.

Chhattisgarh Journal of Science and Technology, 2022

The authors report upon the effect of Chromium (III) ion doping on thecrystal chemistry, structur... more The authors report upon the effect of Chromium (III) ion doping on thecrystal chemistry, structure, cation distribution and Raman spectroscopic phonon mode characteristics of cobalt ferrite (CoFe2O4) nano structured synthesized by a facile and costeffectiveone-step aqueous sol-gel synthesis route. Crystal structure analysis suggests that the Cr (III) ion doped cobalt ferrites, CoFe2-xCrxO4with x = 0.0, 0.1, 0.2 and 0.3 compositions were crystallized into a cubicinverse spinel structurewith Oh 7 (Fd-3m)space group (SG#227). After, Cr 3+ ions doping the lattice parameter of doped samples were decreased due to the depletion of Fe ions at the tetrahedral A site and that further generated compressive lattice strain to reduce the lattice parameter. The results of Raman spectroscopic studies are in good agreement with the PXRD results. Strikingly,Raman shifts assigned to the most intense A1g mode were red shifted towards lower wavenumber due to the modulation in the cationic charge distribution at the tetrahedral and octahedral lattice site after Cr (III) ions incorporation at the octahedral site.

During this decade,cubic structure spinel nano-ferriteshas got great attention from various field... more During this decade,cubic structure spinel nano-ferriteshas got great attention from various fields,i.e., physics, chemistry, biology, medicine, materials science, and engineeringbecause of their desirable structural, electrical, magnetic, anddielectric properties along with good biocompatibility and low toxicity.These ferrite materials have been used in a broader way for technological and medical applications such as magnetocaloric refrigerators,

Materials Today: Proceedings

Chhattisgarh Journal of Science & Technology, 2021

We successfully synthesized SrMoO4 by Sol-Gel (auto combustion) Method at different calcinations ... more We successfully synthesized SrMoO4 by Sol-Gel (auto combustion) Method at different calcinations temperatures 600 0C, 700 0C,
800 0C and 900 0CC with fixed time period. The FTIR and Raman Data confirms that our sample is prepared and it is a single phase material.
The UV-Visible spectra gives the optical energy band gap through WOOD and TAUC formula. The splitting between obtained energy band
gaps of SrMoO4 samples are increasing with increase in calcinations temperature. This could be due to increase in particle size with increasing
calcination temperature and order-disorder transition of SrMoO4.

Vibrational Spectroscopy, 1996

ABSTRACT

<jats:p>In this paper, we have studied the EPR spectra, X-ray diffraction and Raman Analysi... more <jats:p>In this paper, we have studied the EPR spectra, X-ray diffraction and Raman Analysis, Microstructures-morphology of the Ceria NPs calcined at different temperatures of 700 °C, 850 °C ,these materials have been synthesized by Co precipitation (CPT) method by using Cerium tri-nitrate hexahydrate and potassium carbonate solutions. Then synthesized precipitate was heated at 70 °C for 20 hour. Slow grinding of the precipitate and calcined for 3 hours at different temperatures viz. 700 °C and 850 °C to form fine Cerium oxide powder-Ceria NPs. The EPR measurements were made using continuous wave spectrometer (X-band, Bruker Biospin EMX Plus). The g values were obtained by using diphynelpirichylhydrageyl (DPPH-C<jats:sub>18</jats:sub>H<jats:sub>12</jats:sub>N<jats:sub>5</jats:sub>O<jats:sub>6</jats:sub>) sample and got g value is around 1.97. This g tensor is decreased when the calcined temperature are increased, EPR parameters are also changed as the calcined temperature increases. When the calcined temperature is increased from 700 °C to 850 °C, a doublet separated, intensity increased. The X-Ray diffraction pattern shows the nature of the Ceria NPs crystal, with a cubic structure and got the lattice parameters 5.392 Å for samples calcined at temperature of 700 °C and 5.357 Å at 850 °C which shows decreasing trend in lattice parameter with calcination temperature. The intensity of Raman peaks is also shifted upwards with a rise in temperature. This intensity difference could be because of the rise in vibrational amplitudes of the closest neighboring bonds because of the increase in particle size 11.3± 1.0 to 15.6± 1.0 nm at calcination temperatures of 700 °C and 850 °C and the Raman peak of peak I, 461 cm<jats:sup>-1</jats:sup> and peak II, 463 cm<jats:sup>-1</jats:sup> respectively. Other peaks were not observed in this Raman pattern. The EDS analysis confirms the presence of the Ce and O atoms in the synthesized samples. Spherical shapes and homogeneously distributed Ceria NPs and a rather tendency for agglomeration were confirmed.</jats:p>

Journal of Physics: Conference Series

In this paper, we present the investigations of Electron Paramagnetic Resonance (EPR) on Mn site ... more In this paper, we present the investigations of Electron Paramagnetic Resonance (EPR) on Mn site substituted Pr based Doped rare Earth Manganites i.e. Pr0.60Ca0.40MnO3 and Pr0.60Ca0.40Mn0.85Zn0.15O3. Changes in physical properties as lattice parameters, average valence of Mn site was observable of those manganites. X-ray diffraction pattern shows that both Pr0.60Ca0.40MnO3 and Pr0.60Ca0.40Mn0.85Zn0.15O3 have single phase and without the other secondary or impurity phase and indexed supported the Pbnm space group. The value of x in Pr0.60Ca0.40Mn1-xZnxO3 increases, the average valence V was increased except for a fixed composition, i.e. x remains unchanged, the average valence V was decreased as we go from less valency to high valency (i.e., from divalent to trivalent and from trivalent to tetravalent. The EDXS analysis of those materials shows good homogeneity, but there are experimental errors in composition. It is seen from the SEM images that is formed in different shape grains. ...

AIP Conference Proceedings, 2021

The aligned YBa2Cu3O7-δ(YBCO) superconducting materials were prepared by unique annealing method ... more The aligned YBa2Cu3O7-δ(YBCO) superconducting materials were prepared by unique annealing method on a Gold foil. The structural and other properties of these superconducting materials have been studied i.e. X-ray diffraction, Scanning Electron Micrograph Magnetization and resistivity measurements. The study shows that the change in the Gold doping concentration in these superconducting materials from 0.1 to 3% affected the transition temperature range from 89K to 94K and the critical current density noticeably. The current density measured from the M-H curve is 2 × 104 Acm-2 by Bean Model. Densification and elongated alignment ≈200 µm longs are observed in these materials.

Microscopy and Microanalysis, 2009

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia... more Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

Materials Today: Proceedings, 2021

Gingers are improper in shape, so the peeling process is very time consuming. Gingers of equal we... more Gingers are improper in shape, so the peeling process is very time consuming. Gingers of equal weight (approximate) were taken and washed in tap water and then were drained to remove the excess water and done for the primary trials. We have studied the impact of infrared heating and microwave heating parameters on physical and peeling properties of ginger and done the comparative study of infrared and microwave assisted ginger peeling. ANOVA represents that both MW power and MW time had a important (p < 0.01) effect on moisture loss, peel loss and peelability. The moisture loss, peel loss and peelability increased with the increased in MW power but at high power peel loss and peelability decreased. The peel loss and moisture loss increased with the increase in MW time. Peelability decreased at high MW time. In infrared assisted peeling ANOVA represents that distance had a important (peelabilty is <0.01), effect on moisture loss, peel loss and peelability. The peel loss showed no important (p > 0.05) changes with change in treatment time. Peel loss and peelability were significantly (p < 0.05) affected by treatment time. The moisture loss, peel loss and peelability decreased with increase in distance between heating source and sample. The moisture loss increased with increase in treatment time but peelability decreased with the same. Microwave heating showed the minimum (0.46%) moisture loss, and minimum (0.46%) peel loss whereas infrared heating gave the (35.5%) maximum peelability.