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Kadam R.H.,Materials Science Research Laboratory | Biradar A.R.,Rajarshi Shahu Mahavidyalaya | Mane M.L.,Dr. Babasaheb Ambedkar Marathwada University | Shirsath S.E.,Vivekanand College | Shirsath S.E.,Shinshu University
Journal of Applied Physics | Year: 2012

Ferrite samples of Li + substituted MnFe 2O 4 nano particles were synthesized by sol-gel auto-combustion method. The samples were obtained by annealing at relatively low temperature at 600 °C and characterized by x-ray diffraction, transmission electron microscopy, vibrating sample magnetometry, and infrared (IR) spectroscopy. Lattice parameter, x-ray density, specific surface area, and porosity are found to increase, whereas bulk density and crystallite size showed the decreasing trend with the Li + content. Splitting of major absorption bands related to Li + substituted ferrites were observed in IR spectra. Substitution of Li + ions for Fe 3 caused a decrease in the saturation magnetization from 75.69 to 58.57 emu/g and the coercivity increased from 157 to 308 Oe. DC resistivity decreases with increase in Li + content. The temperature dependent results indicate that the values of dielectric constant (ε′) and loss tangent (ε″) increase with the increase in temperature. © 2012 American Institute of Physics. Source

Mane D.R.,Balbhim College | Patil S.,Balbhim College | Birajdar D.D.,Balbhim College | Kadam A.B.,Jawahar Mahavidyalaya andoor | And 2 more authors.
Materials Chemistry and Physics | Year: 2011

Li0.5CrxFe2.5-xO4 powders with fine sized particles were successfully synthesized by sol-gel auto combustion, using lithium nitrate, ferric nitrate, chromium nitrate, and citric acid as the starting materials. The process takes only a few minutes to obtain as-prepared Cr-substituted lithium ferrite powders. The resultant powders were annealed at 600 °C for 4 h and investigated by thermogravimeter/differential thermal analyzer (TG/DTA), X-ray diffractometer (XRD) and vibrating sample magnetometer (VSM). Lattice parameter, bulk density and particle size are found to decrease with increasing Cr concentration, whereas X-ray density and porosity showed an increasing trend with the Cr content. Cation distribution indicates that the chromium ion occupy octahedral B-site. The magnetic moments calculated from Neel's molecular field model are in agreement in the experiment result, which indicates that the saturation magnetization decreases linearly from 37.36 to 4.27 emu/g with increasing Cr3+ content. However, coercivity, it increases with the Cr3+ substitution. © 2010 Elsevier B.V. All rights reserved. Source

Shirsath S.E.,Vivekanand College | Shirsath S.E.,Shinshu University | Kadam R.H.,Materials Science Research Laboratory | Mane M.L.,S.G.R.G. Shinde Mahavidyalaya | And 4 more authors.
Journal of Alloys and Compounds | Year: 2013

A series of spinel ferrites, Li0.5Co1.5xFe 2.5-xO4, with x = 0.0, 0.25, 0.50, 0.75 and 1.0 were successfully synthesized by sol-gel auto combustion method, aiming to study the relationship between structural and magnetic interactions related to the concentration of the substituted cobalt cations. X-ray diffraction measurements were employed for analyzing the structure, lattice parameter, density, porosity and crystallite size of the prepared samples. Samples have the cubic spinel structure with a small amount of α- Fe2O3 and γ-Fe2O3. As the Co2+ ions increases, hematite and maghemite phases disappear and the crystals form the single phase spinel structure with the cation ordering on octahedral sites. Lattice constant (a) increases from 8.331 to 8.423 A with increase in Co2+ substitution. Particle size estimated from the transmission electron microscopy images, and is ranging from 12 to 23 nm. Infrared spectroscopy measurements were carried out to study the band position and structure of the sample. Saturation magnetization decreased linearly from 41.21 to 28.84 A m2/kg with an increase in Co2+ content. It was found that coercivity increased with the Co2+ substitution from 8678 to 75636 A/m. The samples were zero field cooled to 100 K. Typical blocking effects were observed below about 253 K. Curie temperature (TC) were obtained from AC susceptibility and permeability measurements shows the decreasing trend with Co2+ substitution, indicating the weakening in A-B interactions. Permeability decreased with the increase in Co2+ substitution due to the combine effect of magnetization and magnetocrystalline anisotropy. © 2013 Elsevier B.V. All rights reserved. Source

Mane D.R.,Belbhim College | Birajdar D.D.,Belbhim College | Patil S.,Belbhim College | Shirsath S.E.,Vivekanand College | Kadam R.H.,Materials Science Research Laboratory
Journal of Sol-Gel Science and Technology | Year: 2011

Cu0.7- x Co x Zn0.3Fe2O 4 (0 ≤ x ≤ 0.5) nanoparticles are prepared by sol-gel auto combustion method, using copper nitrate, zinc nitrate, ferric nitrate, cobalt nitrate, and citric acid as the starting materials. The process takes only a few minutes to obtain as-received Co-substituted Cu-Zn ferrite powders. X-ray diffraction (XRD), vibrational sample magnetometer and thermo gravimetric analysis are utilized in order to study the effect of variation in the Co substitution and its impact on particle size, lattice constant, density, cation distribution and magnetic properties like magnetization, coercivity, remanent magnetization, ferritization temperature and associated water content. Lattice parameter found to increase with increasing Co content, whereas X-ray density, bulk density, particle size showed decreasing trend with the Co content. Cation distribution indicates that the Co and Cu ion show preference towards octahedral [B] site, Zn occupy tetrahedral (A) site whereas Fe occupy both tetrahedral (A) and octahedral [B] site. Redistribution of cations takes place for x > 0.3. Saturation magnetization (Ms) increases from 52.99 to 79.62 emu/g (x ≤ 0.3), for x > 0.3 Ms decreases with increase in Co content x. However, coercivity, magnetocrystalline anisotropy and remanent magnetization increases with the Co2+ substitution. © 2010 Springer Science+Business Media, LLC. Source

Shirsath S.E.,Dr. Babasaheb Ambedkar Marathwada University | Toksha B.G.,Dr. Babasaheb Ambedkar Marathwada University | Kadam R.H.,Materials Science Research Laboratory | Patange S.M.,Materials Science Research Laboratory | And 3 more authors.
Journal of Physics and Chemistry of Solids | Year: 2010

The ferrite samples of a chemical formula Ni0.5-xMn xZn0.5Fe2O4 (where x=0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) were synthesized by solgel auto-combustion method. The synthesized samples were annealed at 600 °C for 4 h. An analysis of X-ray diffraction patterns reveals the formation of single phase cubic spinel structure. The lattice parameter increases linearly with increase in Mn content x. An initial increase followed by a subsequent decrease in saturation magnetization with increase in Mn content is observed showing inverse trend of coercivity (Hc). Curie temperature decreases with increase in Mn content x. The initial permeability is observed to increase with increase in Mn content up to x=0.3 followed by a decrease, the maximum value being 362. Possible explanation for the observed structural, magnetic, and changes of permeability behavior with various Mn content are discussed. © 2010 Elsevier Ltd. Source

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