Jitendra S. Kounsalye

Influence of Ti 4+ ion substitution on structural, electrical and dielectric properties of Li 0.5 Fe 2.5 O 4 nanoparticles

The extent study deals with the structural, electrical and dielectric properties of tetravalent Ti4+ ion substituted lithium ferrite nanoparticles synthesized via sol–gel auto combustion technique with chemical formula Li0.5+0.5xTixFe2.5−1.5xO4 (where 0.0 ≤ x ≤ 1.0 in step of 0.2). The synthesized nanoparticles were characterized by X-ray diffraction technique (XRD). The XRD analysis reveals single phase cubic spinel structure of synthesized samples. The crystallite size calculated from Scherrer’s formula and grain size by linear intercept method using field emission scanning electron microscopy (FE-SEM) images, confirms the nanocrystalline nature of the samples. Infrared (IR) spectroscopy shows principle absorption bands for spinel structure. The DC resistivity at room temperature and as a function of temperature was studied using the two-probe technique. DC electrical resistivity of the samples increases with titanium substitution. The frequency dependence of dielectric properties was studied using LCR-Q meter, the dielectric parameters were found to decrease after substitution of titanium ions.

Temperature dependent viscosity of cobalt ferrite / ethylene glycol ferrofluids

In the present work, cobalt ferrite / ethylene glycol ferrofluid is prepared in 0 to 1 (in the step of 0.2) volume fraction of cobalt ferrite nanoparticles synthesized by co-precipitation method. The XRD results confirmed the formation of single phase spinel structure. The Raman spectra have been deconvoluted into individual Lorentzian peaks. Cobalt ferrite has cubic spinel structure with Fd3m space group. FT-IR spectra consist of two major absorption bands, first at about 586 cm−1 (υ1) and second at about 392 cm−1 (υ2). These absorption bands confirm the formation of spinel-structured cobalt ferrite. Brookfield DV-III viscometer and programmable temperature-controlled bath was used to study the relationship between viscosity and temperature. Viscosity behavior with respect to temperature has been studied and it is revealed that the viscosity of cobalt ferrite / ethylene glycol ferrofluids increases with an increase in volume fraction of cobalt ferrite. The viscosity of the present ferrofluid was found to decrease with increase in temperature.In the present work, cobalt ferrite / ethylene glycol ferrofluid is prepared in 0 to 1 (in the step of 0.2) volume fraction of cobalt ferrite nanoparticles synthesized by co-precipitation method. The XRD results confirmed the formation of single phase spinel structure. The Raman spectra have been deconvoluted into individual Lorentzian peaks. Cobalt ferrite has cubic spinel structure with Fd3m space group. FT-IR spectra consist of two major absorption bands, first at about 586 cm−1 (υ1) and second at about 392 cm−1 (υ2). These absorption bands confirm the formation of spinel-structured cobalt ferrite. Brookfield DV-III viscometer and programmable temperature-controlled bath was used to study the relationship between viscosity and temperature. Viscosity behavior with respect to temperature has been studied and it is revealed that the viscosity of cobalt ferrite / ethylene glycol ferrofluids increases with an increase in volume fraction of cobalt ferrite. The viscosity of the present ferrofluid was found to...

Rietveld refinement and electrical properties of LiTiFeO4

Nanoparticles of Ti4+ substituted lithium ferrite LiTiFeO4 were prepared by the sol-gel auto combustion method. The sintered sample was characterized by X-ray diffraction to study the structural properties. The crystallite size obtained by Scherrer formula using XRD data is 22nm. The Rietveld refinement of the obtained XRD pattern was carried out using full-proof program. The electrical measurements as DC electrical resistivity and I-V measurement were carried out by two-probe technique and I-V characteristics. The semiconducting behaviour of the investigated sample was observed. The Ohmic nature was revealed by I-V characteristic.Nanoparticles of Ti4+ substituted lithium ferrite LiTiFeO4 were prepared by the sol-gel auto combustion method. The sintered sample was characterized by X-ray diffraction to study the structural properties. The crystallite size obtained by Scherrer formula using XRD data is 22nm. The Rietveld refinement of the obtained XRD pattern was carried out using full-proof program. The electrical measurements as DC electrical resistivity and I-V measurement were carried out by two-probe technique and I-V characteristics. The semiconducting behaviour of the investigated sample was observed. The Ohmic nature was revealed by I-V characteristic.

Symmetry transition via tetravalent impurity and investigations on magnetic properties of Li0.5Fe2.5O4

The present study, deals with the phase symmetry transformation of lithium ferrite after introducing tetravalent (Ti4+) impurity. The sol-gel auto combustion technique was adopted for the synthesis of nanoparticle samples with generic chemical formula Li0.5Fe2.5O4 and Li0.55Ti0.10Fe2.35O4. The synthesized nanoparticles were characterized by X-ray diffraction (XRD) technique for structural analysis. The XRD patterns show the single phase cubic structure without any impurity phase but the P4332 to Fd-3m transformation was observed after introducing Ti4+ impurity. The Nano size of the synthesized particles was confirmed by crystallite size (~20nm) calculated using Debye-Scherrer’s formula. The Fourier transform infrared spectroscopy (FTIR) studies shows shifting of band frequencies which reflect the structural changes after tetravalent substitutional impurities. The magnetic properties were studied through pulse field hysteresis loop (M-H loop) technique at room temperature, the M-H loops showdecrease in magnetic properties afternonmagnetic Ti4+ ion substitution. This is attributed to transition of inverse spinel structure of lithium ferrite to random spinel structure.The present study, deals with the phase symmetry transformation of lithium ferrite after introducing tetravalent (Ti4+) impurity. The sol-gel auto combustion technique was adopted for the synthesis of nanoparticle samples with generic chemical formula Li0.5Fe2.5O4 and Li0.55Ti0.10Fe2.35O4. The synthesized nanoparticles were characterized by X-ray diffraction (XRD) technique for structural analysis. The XRD patterns show the single phase cubic structure without any impurity phase but the P4332 to Fd-3m transformation was observed after introducing Ti4+ impurity. The Nano size of the synthesized particles was confirmed by crystallite size (~20nm) calculated using Debye-Scherrer’s formula. The Fourier transform infrared spectroscopy (FTIR) studies shows shifting of band frequencies which reflect the structural changes after tetravalent substitutional impurities. The magnetic properties were studied through pulse field hysteresis loop (M-H loop) technique at room temperature, the M-H loops showdecrease in mag...