Razia Nongjai

Magnetic and electrical properties of In doped cobalt ferrite nanoparticles

Nanoparticles of CoFe2O4 and CoIn0.15Fe1.85O4 ferrites were prepared by citrate gel route and characterized to understand their structural, electrical, and magnetic properties. X-ray diffraction and Raman spectroscopy were used to confirm the formation of single phase cubic spinel structure. The average grain sizes from the Scherrer formula were below 50 nm. Microstructural features were obtained by scanning electron microscope and compositional analysis by energy dispersive spectroscopy. The hysteresis curve shows enhancement in coercivity while reduction in saturation magnetization with the substitution of In3+ ions. Enhancement of coercivity is attributed to the transition from multidomain to single domain nature. Electrical properties, such as dc resistivity as a function of temperature and ac conductivity as a function of frequency and temperature were studied for both the samples. The activation energy derived from the Arrhenius equation was found to increase in the doped sample. The dielectric cons...

Study of structural property of Co ferrite thin film grown by pulsed laser deposition technique

Thin film of Cobalt Ferrite was deposited on Si (1 0 0) substrate using Pulsed Laser Deposition (PLD) technique. The deposited film was characterized by X–ray Diffraction (XRD), X–ray reflectivity (XRR), Rutherford Backscattering Spectroscopy (RBS) and Raman Spectroscopy and was found to be single phase, textured along (1 1 1) directions and approximately matching the stoichoimetry of the target with negligible strain. The film had a very uniform and flat surface. Raman spectroscopy measurement further confirmed the formation of single phase cubic spinel structure. T2g Raman mode was missing from the spectra which may be due to cation redistribution and crystallite size effect.

STRUCTURAL AND MAGNETIC PROPERTIES OF La0.67Sr0.33Mn0.93Zn0.07O3 MANGANITE

The structural and magnetic measurements have been carried out on La0.67Sr0.33Mn0.93Zn0.07O3 (LSMZO) polycrystalline sample. The sample has been prepared through Sol-Gel route. X-ray diffraction (XRD) pattern confirms the single phase nature of the sample with orthorhombic crystal symmetry. Field dependent magnetization shows the hysteresis loop with very low coercive field and the magnetization does not saturate up to the field of 5000 gauss in magnitude.

Study Of Structural And Dielectric Properties Of Ni‐Mg Ferrite Nanoparticles

Ferrite nanoparticles of basic composition Ni0.7Mg0.3Fe2‐xAlxO4 (0.0≤x≤0.5) were prepared through citrate gel method and characterized using XRD, TEM and dielectric spectroscopy techniques. The dielectric properties were studied as a function of frequency (42 Hz‐5 MHz) at room temperature. The average particle size has been found between 8–17 nm. The dispersion in dielectric properties and ac conductivity (σac), with frequency reveals that the dispersion is due to Maxwell‐Wagner type of interfacial polarization in general and the hopping of charge between Fe2+ and Fe3+ as well as between Ni2+ and Ni3+ ions at B‐sites. The dielectric loss tangent (tan δ) shows abnormal behavior for the compositions 0.3, 0.4 and 0.5 which has been explained in the light of Rezlescue model.