Entity

Time filter

Source Type


Shinde A.B.,Aabasaheb Garware College | Pandit A.A.,Yashwant College Sillod | Kale C.M.,Indraraj Arts Commerce and Science College | Shengule D.R.,Sardar Dalipsingh Commerce and Science College | Jadhav K.M.,Dr. Babasaheb Ambedkar Marathwada University
Journal of Superconductivity and Novel Magnetism | Year: 2015

Series of zinc-substituted nickel ferrite, Ni1−x ZnxFe2O4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0), nanoparticles were synthesized at low temperature by using sol–gel auto-combustion method. Powder X-ray diffraction confirmed the single-spinel structure of the synthesized Ni–Zn ferrite nanocrystals with average crystallite size was found to be 30 nm which is close to that of critical size for exhibiting superparamagnetism which was further verified from Mössbauer spectroscopic studies. The stoichiometric analysis of the ferrite samples carried out by employing energy-dispersive X-ray spectroscopy is found to be as expected. Results of infrared spectroscopic studies carried out on these superparamagnetic ferrite nanocrystals are reported in this paper. The tetrahedral and octahedral absorption band frequencies suggested the spinel structure of the ferrite samples and its behavior with zinc content x is attributed to the nanosize effect and occupation of zinc cations at the octahedral [B] sites. Further, the force constants are found to be in the reported range of that for ferrites. © 2014, Springer Science+Business Media New York. Source


Raut A.V.,Sardar Dalipsingh Commerce and Science College | Jadhav S.A.,Sardar Dalipsingh Commerce and Science College | Shengule D.R.,Sardar Dalipsingh Commerce and Science College | Jadhav K.M.,Dr. Babasaheb Ambedkar Marathwada University
Journal of Alloys and Compounds | Year: 2016

Magnetic nanoparticles of CoFe2O4 NPs were fabricated using simple sol-gel auo-combustion synthesis and irradiated with total gamma dose of 50 kGy and 100 kGy maintaining a dose rate of 0.7 kGy/h. More emphasis was given for calculating an error free value of Lattice constant (α) by re-evaluating Debay-Sherrer value with Nelson-Riley extrapolation function (N-R). Bradley-jay function (B-J) and specimen mis-alignment error was elaborated while discussing the unit cell parameters. SEM images described the irradiation effects on polycrystalline and aggregated morphology of CoFe2O4 NPs. The prominent absorption bands (ν1, ν2, ν3, ν4) in room temperature FTIR spectra confirmed the formation of ferrite phase and stretching vibrations in γ-irradiated CoFe2O4 NPs. Decreasing DC-resistivity, increasing drift mobility and the measured range of activation energy (0.120-0.281 eV) was discussed as a function of γ-irradiation indicating ferrimagnetic behaviour of CoFe2O4 NPs. Several magnetic parameters (Mr, Hc, HK, nBe) were determined from the M-H loop recorded at room temperature. Magnetic anisotropy constant (K1) of gamma irradiated CoFe2O4 NPs was deduced using 'Law of approach' (LA) fit to saturation. © 2016 Elsevier B.V. All rights reserved. Source


Raut A.V.,Sardar Dalipsingh Commerce and Science College | Barkule R.S.,Sardar Dalipsingh Commerce and Science College | Shengule D.R.,Sardar Dalipsingh Commerce and Science College | Jadhav K.M.,Dr. Babasaheb Ambedkar Marathwada University
Journal of Magnetism and Magnetic Materials | Year: 2014

Structural morphology and magnetic properties of the Co 1-xZnxFe2O4 (0.0≤x≥1.0) spinel ferrite system synthesized by the sol-gel auto-combustion technique using nitrates of respective metal ions have been studied. The ratio of metal nitrates to citric acid was taken at 1:3. The as prepared powder of cobalt zinc ferrite was sintered at 600 C for 12 h after TG/DTA thermal studies. Compositional stoichiometry was confirmed by energy dispersive analysis of the X-ray (EDAX) technique. Single phase cubic spinel structure of Co-Zn nanoparticles was confirmed by XRD data. The average crystallite size (t), lattice constant (a) and other structural parameters of zinc substituted cobalt ferrite nanoparticles were calculated from XRD followed by SEM and FTIR. It is observed that the sol-gel auto-combustion technique has many advantages for the synthesis of technologically applicable Co-Zn ferrite nanoparticles. The present investigation clearly shows the effect of the synthesis method and possible relation between magnetic properties and microstructure of the prepared samples. Increase in nonmagnetic Zn2+ content in cobalt ferrite nanoparticles is followed by decrease in nB, Ms and other magnetic parameters. Squareness ratio for the Co-ferrite was 1.096 at room temperature. © 2014 Elsevier B.V. Source


Kale C.M.,Indraraj Arts Commerce and Science College | Aghav P.S.,Sardar Dalipsingh Commerce and Science College | Shengule D.R.,Sardar Dalipsingh Commerce and Science College | Jadhav K.M.,Dr. Babasaheb Ambedkar Marathwada University
Journal of Superconductivity and Novel Magnetism | Year: 2014

Zinc-substituted nickel ferrite (Ni 1-x Zn x Fe 2 O 4 with x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) nanoparticles were synthesized by solgel auto-combustion technique at low temperature and characterized by using X-ray diffraction, scanning electron microscopy, pulse field hysteresis loop technique, and Mossbauer spectroscopy. X-ray diffraction studies confirmed the formation of single-phase spinel structure of the prepared ferrite samples with average crystallite size of 30 nm, very close to that of the critical size for nanoparticles exhibiting superparamagnetism. Scanning electron micrographs of the ferrite samples showed uniform spherical morphology of nanograins with homogenous microstructure. Further investigations on magnetic properties by pulse field hysteresis loop technique and Mossbauer spectroscopy indicated the presence of superparamagnetic phases in the ferrite samples attributed to occupation of octahedral [B] sites by zinc ions in these Ni-Zn samples and also to the nanometer sizes of the ferrite particles. Magnetic behavior of the Ni-Zn ferrite system is in agreement, initially, with Neel's two-sublattice collinear model and then with the Yafet-Kittel model for samples with higher zinc content (x ≥ 0.4). Value of hyperfine splitting is found to decrease with increase in zinc content and is attributed to the reduction in particle size giving rise to superparamagnetism. Other Mossbauer parameters like quadrupole splitting and the isomer shift are within the reported range for those of ferrites with spinel structure. © 2014 Springer Science+Business Media New York. Source


Raut A.V.,Sardar Dalipsingh Commerce and Science College | Jadhav S.A.,Sardar Dalipsingh Commerce and Science College | Shengule D.R.,Sardar Dalipsingh Commerce and Science College | Jadhav K.M.,Dr. Babasaheb Ambedkar Marathwada University
Journal of Sol-Gel Science and Technology | Year: 2016

Abstract: Nanocrystalline spinel ferrite was prepared by sol–gel auto-combustion technique and sintered at 600 °C for 12 h. Single-phase cubic spinel structure of zinc ferrite was confirmed through X-ray diffractometry. Several structural and magnetic properties of ZnFe2O4 NPs were studied after Co60γ-irradiation with total gamma dose of 50 and 100 kGy. An average crystallite size was determined from the full width at half maximum of strongest reflection (311) by using Scherrer’s approximation. Williamson–Hall plot (graph against βcosθ and 4sinθ) was used to re-evaluate the measured crystallite size and to estimate the strain distribution in terms of η%. Lattice constant (α) initially increased slightly to 8.441 Å with γ-50 kGy and then decreased dramatically with total dose of γ-100 kGy. Frustrated behaviour in peak shift to lower and higher 2θ side can be seen in XRD after γ-irradiation to ZnFe2O4 NPs. FT-IR spectra confirmed the formation of ferrite phase and redistribution of cations in (A) and [B] sites of ZnFe2O4 spinel structure. In the first derivative peak of ESR spectroscopy, gyroscopic spitting factor (g-value) and linewidth (∆HPP) were used to deliberate the γ-radiation damage in investigated ferrimagnetic nanoparticles. Experimental results revealed that the saturation magnetization (Ms), coercivity (Hc) and magneton number (nB) of ZnFe2O4 NPs were found to be increased after gamma irradiation dose of γ-100 kGy. Graphical Abstract: [Figure not available: see fulltext.] © 2016 Springer Science+Business Media New York Source

Discover hidden collaborations