Ashok V. Humbe

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.

Polyethylene glycol coated CoFe2O4 nanoparticles: A potential spinel ferrite for biomedical applications

The structural and magnetic properties of the polyethylene glycol (PEG) coated cobalt spinel ferrite (CoFe2O4) nanoparticles have been reported in the present study. CoFe2O4 nanoparticles were prepared by sol-gel auto-combustion method using citric acid + ethylene glycol as a fuel. The prepared powder of cobalt ferrite nanoparticles was annealed at 600°C for 6h and used for further study. The structural characterization of CoFe2O4 nanoparticles were carried out by X-ray diffraction technique. The X-ray analysis confirmed the formation of single phase cubic spinel structure. The crystallite size, Lattice constant and X-ray density of the PEG coated CoFe2O4 nanoparticles were calculated by using XRD data. The presence of PEG on CoFe2O4 nanoparticles and reduced agglomeration in the CoFe2O4 nanoparticles were revealed by SEM studies. The magnetic properties were studied by pulse field hysteresis loop tracer technique at a room temperature. The magnetic parameters such as saturation magnetization, remanence m...

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...