Richa Sharma; N. C. Mehra; R. P. Tandon
Abstract
In the present work, the composite series (1-x) Ba0.94Ca0.06TiO3 - (x) Ni0.7Co0.1Zn0.2Fe2O4 (where x = 0.1, 0.2, 0.3 and 0.4 wt. fraction) was synthesized by solid state reaction method followed by conventional sintering. The structure and morphology of prepared samples were examined using X-ray diffractometer ...
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In the present work, the composite series (1-x) Ba0.94Ca0.06TiO3 - (x) Ni0.7Co0.1Zn0.2Fe2O4 (where x = 0.1, 0.2, 0.3 and 0.4 wt. fraction) was synthesized by solid state reaction method followed by conventional sintering. The structure and morphology of prepared samples were examined using X-ray diffractometer (XRD) and scanning electron microscopy (SEM), respectively. In addition, dielectric constant (ε΄) and loss tangent (tan δ) of prepared samples were measured as a function of frequency and temperature. The room temperature values of dielectric constant (ε΄) of composite samples are found to decrease from 529.29 to 159.52 as ferrite content increased from x = 0.1 to x = 0.4 at 1 kHz frequency. Moreover, in the dielectric constant vs. temperature plots of the composite samples, ferroelectric to paraelectric phase transition of pure Ba0.94Ca0.06TiO3 is observed. Furthermore, ferroelectric and magnetic properties of the composite samples were studied at room temperature. With increasing addition of the ferrite content in the composites, the ferroelectric properties get weakened and the magnetic behavior of the composite samples improved. The maximum values of saturation magnetization ( ) and remanant magnetization ( ) are 22.52 emu/gm and 3.39 emu/gm, respectively, for composite sample containing 0.4 wt. fraction Ni0.7Co0.1Zn0.2Fe2O4. Copyright © 2017 VBRI Press.
Azizurrahaman Ansari; Vishal Kumar Chakradhary; M. J. Akhtar
Abstract
In this article, an effort is made to synthesize the nickel ferrite nanoparticles via chemical co-precipitation method using the metal nitrates as precursors. The x-ray diffraction pattern of the as-synthesized powder sample indicates the formation of nickel ferrite with iron oxide and other impurity ...
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In this article, an effort is made to synthesize the nickel ferrite nanoparticles via chemical co-precipitation method using the metal nitrates as precursors. The x-ray diffraction pattern of the as-synthesized powder sample indicates the formation of nickel ferrite with iron oxide and other impurity phases. The heat treatment of the as-synthesized powder at 600oC assists in the formation of inverse spinel phase of nickel ferrite accompanying with some fraction of iron oxide phase. The field emission scanning electron microscopy of the heat treated sample reveals the irregular particle size and shape with fine microstructures, while as-synthesized sample shows the lamina like particle morphology. The magnetization curve(M-H curve) of the heat treated sample shows the ferrimagnetic behavior with very small (negligible) values ofremanent magnetization and coercive field. Such type of magnetic characteristic indicates the signature of superparamagnetism (Mr ~ 0, Hc ~ 0) in the heat treated nickel ferrite nanoparticles with significant value of the saturation magnetization (Ms). The superparamagnetic effect in the nickel ferrite particles has great potential in the field of biomedicine for certain applications such as the effective drug delivery, and for enhancing the contrast in case of magnetic resonance imaging. Copyright © 2016 VBRI Press.
Sanatombi Sorokhaibam; Ibetombi Soibam; Sumitra Phanjoubam
Abstract
Substituted lithium ferrite having the chemical formula Li0.35 Ni0.1 Mn0.1 Zn0.2 Fe2.35 O4 have been synthesized by the citrate precursor method. The sample was given pre-sintering at 650oC in a conventional furnace. Final sintering was carried out at 900oC in a conventional surface and another ...
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Substituted lithium ferrite having the chemical formula Li0.35 Ni0.1 Mn0.1 Zn0.2 Fe2.35 O4 have been synthesized by the citrate precursor method. The sample was given pre-sintering at 650oC in a conventional furnace. Final sintering was carried out at 900oC in a conventional surface and another in a microwave furnace. The spinel phase structure of the conventional (CS) and microwave sintered (MS) samples was confirmed by the XRD patterns. From the analysis of XRD data, the crystallite size of the samples was estimated and smaller crystallite size was observed in the microwave sintered sample. Scanning Electron Microscopy (SEM) was also carried out. The dielectric studies were investigated. Room temperature dielectric constant ( ) and dielectric loss (tan d) were studied as a function of frequency. Experimental results show dispersion for variation of dielectric constant and dielectric loss tangent with frequency for both CS and MS sample. However, microwave sintered sample show lower dielectric constant and losses. Possible mechanism is being discussed. Copyright © 2016 VBRI Press.
