Kavita Verma

Effect of Mg doping on dielectric properties of CuFe2O4 nanoparticles

Samples of CuFe2O4 and Cu0.5Mg0.5Fe2O4 ferrite nanoparticles were successfully prepared by chemical co-precipitation method. X-ray diffraction pattern infers that both the samples are in single phase with Fd3m space group. Slight reduction in the lattice parameter of Cu0.5Mg0.5Fe2O4 (∼ 42.5 nm) has been observed as compared to CuFe2O4 (∼ 36.3 nm). The dielectric dispersion has been explained on the basis of Maxwell Wagner type of interfacial polarization. The impedance spectra reveal a grain interior contribution to the conduction process.

Investigation of Structural and Magnetic Properties of Cu1−xCdxFe2O4 Ceramic System

Polycrystalline samples of Cu1 − xCdxFe2O4(x = 0.3, 0.4, 0.5, 0.6 and 0.7) were prepared by citrate precursor method. X-ray diffraction results confirm the cubic spinel phase formation with an increase in the lattice parameter with increasing Cd content. Transmission Electron Micrographs show particle size of the samples to lie between 20 nm to 40 nm. By Vibrating Sample Magnetometer, the magnetization curves of the samples under the ZFC and FC conditions show a systematic change (increase) with x ratio. The effect of concentration (x) on magnetic properties is clearly perceptible in the evolution of hysteresis loop indicating that Cu1 − xCdxFe2O4 introduced ferromagnetic contribution.

Structural and optical properties of MgO doped ZnO

Samples of ZnO, Zn0.5Mg0.5O and MgO were prepared by co-precipitation method. X-ray diffraction (XRD) pattern infers that the sample of ZnO is in single-phase wurtzite structure (hexagonal phase, space group P63mc), MgO crystallizes in cubic Fd3m space group and Zn0.5Mg0.5O represents mixed nature of ZnO and MgO lattices. Similar features were observed from Raman spectroscopy. The energy band gaps estimated from UV-Vis spectroscopy are found to be 4.21 and 3.42 eV for ZnO and Zn0.5Mg0.5O samples respectively.

Structural And Magnetic Properties Of Mn And Zn Doped Fe3O4 Nanoparticles

Mn and Zn doped Fe3O4 nanoparticles of size 7.36 and 12.52 nm were prepared by co precipitation method. X‐ray diffraction (XRD) pattern infers that both the samples are in single phase with Fd3m space group, which was further confirmed by Rietveld refinement. Transmission Mossbauer spectra reveals ferrimagnetic nature for Mn doping concentration while into that for Zn doping concentration it shows diamagnetic behaviour. Zn doped nanoparticles shows the superparamagnetic property.

Transport Properties Of Fe{sub 3-x}Ti{sub x}O{sub 4}(x = 0.0 and 0.0206) Epitaxial Thin Films

Fe3−xTixO4 (x = 0 and 0.0206) epitaxial thin films with thickness of 150 nm were prepared by pulsed‐laser deposition technique on SrTiO3 (100), α‐Al2O3 (0001), Si (111) and Float Glass substrates. X‐ray diffraction (XRD) pattern infers that parent and Ti doped magnetites are grown in single phase with (111) orientation. The Verwey transition temperature for Fe3O4 thin films are 121 K (Float Glass), 123 K (SrTiO3), 123.5 K (α‐Al2O3) and 128 K (Si). It is shown that the Ti doping at B site results in the disappearance of Verwey transition in {Tix4+Fe1−x3+Fe2+}O42−.