Entity

Time filter

Source Type

Osmānābād, India

Haralkar S.J.,Kulswamini College | Kadam R.H.,Materials Research Laboratory | More S.S.,Yashwantrao Chavan Mahavidyalaya | Shirsath S.E.,Shinshu University | And 3 more authors.
Materials Research Bulletin | Year: 2013

In this work the nano-structural, magnetic and resistivity properties of Al3+ substituted Mn-Zn ferrites powders were investigated. Mn 0.5Zn0.5AlxFe2-xO4 powders, where x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 were obtained by the sol-gel auto-combustion method. X-ray diffraction data indicate that, after substitution, all the samples consisted of the main spinel phase in combination with a small amount of a foreign Al2O3 phase. The addition of Al3+ resulted in a reduction of particle size and density of the prepared samples. Cation distribution in the present study was estimated by using X-ray diffraction data. The tetrahedral site radii initially increased with Al3+ content while the octahedral site radii decreased with the Al3+ substitution. FTIR spectra show two strong absorption bands at 529-548 cm-1 and 445-452 cm-1 which are the typical bands for the cubic spinel crystal structure. The magnetic properties were measured by employing a vibrating sample magnetometer. It was observed that the saturation magnetization, coercivity and anisotropy field decreased with the increase of Al3+ substitution. Introduction of Al3+ ions into the Mn-Zn ferrite increased the values of the resistivity, especially in the lower temperature range. © 2012 Elsevier Ltd. All rights reserved. Source


Haralkar S.J.,Kulswamini College | Kadam R.H.,Materials Research Laboratory | More S.S.,Yashwantrao Chavan Mahavidyalaya | Shirsath S.E.,Shinshu University | And 3 more authors.
Physica B: Condensed Matter | Year: 2012

The effect of Cr 3+ substitution in Mg-Zn ferrite, with a chemical formula Mg 0.5Zn 0.5Cr xFe 2-xO 4 (x=0.0-1.0), synthesized by a sol-gel auto-combustion reaction is presented in this paper. The resultant powders were investigated by various techniques, including X-ray diffractometry (XRD), transmission electron microscopy (TEM), infrared spectroscopy (IR), vibrating sample magnetometry (VSM), and DC resistivity. The XRD pattern revealed that the cubic spinel structure is maintained for the all the compositions. The particle sizes measured from XRD and TEM are in good agreement with each other. The cation distribution suggests that Mg 2, Cr 3+ and Fe 3 have strong preference towards octahedral B-site. The theoretical lattice constant and experimental lattice constant match each other very well. The IR analysis supports the presently accepted cation distribution. The saturation magnetization decreases linearly with increasing Cr 3+ content. Curie temperatures are obtained by the Laoria and AC susceptibility techniques. The dc resistivity has been investigated as a function of temperature and composition. © 2012 Elsevier B.V. Source


Kale G.H.,Yashwantrao Chavan Mahavidyalaya | Humbe A.V.,Dr. Babasaheb Ambedkar Marathwada University | Birajdar S.D.,Dr. Babasaheb Ambedkar Marathwada University | Shinde A.B.,Abasaheb Garware College | Jadhav K.M.,Dr. Babasaheb Ambedkar Marathwada University
Journal of Materials Science: Materials in Electronics | Year: 2016

The effect of annealing temperature on structural, electrical and dielectric properties of cobalt ferrite nanoparticles has been discussed in this work. The cobalt ferrite nanoparticles were prepared by using sol–gel auto-combustion method taking AR grade nitrates of the constituent ions and l-ascorbic acid as a fuel. The as-prepared powder was annealed at temperatures 600, 800 and 1000 °C. The single phase nature of the prepared samples was confirmed through X-ray diffraction analysis. The particle size was estimated through Scherrer’s formula by considering the most intense peak i.e. (311). The particle size found to be in the nanometer range (32, 43 and 48 nm) and increases with increase in annealing temperature. XRD data was used to obtain other structural parameters and their variation with annealing temperature is discussed. Scanning electron microscopy and infra-red spectroscopy techniques were employed to characterize the prepared cobalt ferrite nanoparticles. IR spectra reveal the characteristic features of the spinel ferrite. The grain size obtained from SEM images was found to vary with annealing temperature. The electrical and dielectric behavior of the cobalt ferrite nanoparticles was studied by using two probe technique as a function of temperature and frequency respectively. The DC electrical resistivity varies inversely with temperature. The dielectric constant, dielectric loss and dielectric loss tangent all decreases exponentially with increasing frequency. The DC electrical resistivity decreases with increasing annealing temperature whereas dielectric parameters increase with increasing annealing temperature. © 2015, Springer Science+Business Media New York. Source


More S.S.,Yashwantrao Chavan Mahavidyalaya | Kadam R.H.,Shrikrishna Mahavidyalaya | Mane D.R.,Shrikrishna Mahavidyalaya | Bichile G.K.,Dr. Babasaheb Ambedkar Marathwada University
Central European Journal of Chemistry | Year: 2010

A series of CoAlxCrxFe2-2xO4 systems (x = 0.1 to 0.5 in steps of x = 0.1) spinel ferrites have been synthesized successfully using wet chemical co-precipitation technique. The samples were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR) and magnetization measurements. The powder XRD patterns confirm the single phase spinel structure for the materials synthesized. X -ray diffraction measurements were performed to yield the lattice constant as function of the amount x corresponding to Al-Cr substitution. Lattice parameters, X-ray density, bulk density and particle size decrease whereas porosity increases with the increase in Al-Cr content, 'x'. Infrared studies show two absorption bands at about 400 cm-1 and 600 cm-1 for octahedral and tetrahedral sites, respectively. Saturation magnetization decreases with the increase in Al-Cr content x. AC magnetic susceptibility measurements were carried out as a function of temperature to measure the Curie temperature, which was found to decrease with Al-Cr content x. The decrease of Curie temperature has been explained by A-B interaction. © 2010 Versita Warsaw and Springer-Verlag Wien. Source


More S.S.,Yashwantrao Chavan Mahavidyalaya | Kadam R.H.,Shrikrishna Mahavidyalaya | Kadam A.B.,Jawahar Mahavidyalaya andoor | Shite A.R.,Yashwantrao Chavan Mahavidyalaya | And 2 more authors.
Journal of Alloys and Compounds | Year: 2010

CoAlxCrxFe2-2xO4 spinel ferrite systems (where x = 0.1 to 0.5 in steps of x = 0.1) were synthesized by wet chemical co-precipitation technique, aiming to study the relationship between cation distribution and concentration of the simultaneous substitution of Al3+ and Cr3+ ions. The Al3+ and Cr 3+ site occupancies show nearly linear composition dependence. The obtained results show, that both Al3+ and Cr3+ ions predominately occupy the octahedral B-site. This is consistent with their preference for large octahedral site energy. The concentration of Al 3+ and Cr3+ ions in octahedral sites increases while that of Fe3+ ions decreases linearly. © 2010 Elsevier B.V. Source

Discover hidden collaborations