A. Paul Blessington Selvadurai

Effect of Ist group elements codoping on structural, optical and magnetic properties of ZnO:Co nanoparticles

In this present work, Co doped and Co and Ist group elements co-doped ZnO samples were prepared by co-precipitation method. The structural properties of the prepared samples were investigated by X-ray diffraction pattern, X-ray photoelectron spectroscopy, scanning electron microscope and Raman spectra measurements. All the results confirmed that the dopant ions are incorporated into the ZnO lattices without any change in the Wurtzite structure and any other secondary phase presented in the samples. The photoluminescence spectroscopy and UV–Drs spectroscopic results were revealed that the presence of lattice defects in prepared samples and the incorporation of dopant ions and their effects on the optical band gap. Magnetic measurements revealed that the prepared samples exhibited room temperature ferromagnetism. The origin of observed ferromagnetism and its enhancement due to doping was analyzed and reported.

Structural and Magnetic properties of Barium Hexaferrrite Prepared through Sol-Gel Auto combustion technique

Barium Hexaferrite nano particles were prepared through glycine assisted sol-gel auto combustion method with a minimal GNR (glycine to nitrate ratio) and the pH values of 4, 6 and 9. The present work aimed at the study on the effect of pH on the synthesis, structural and magnetic properties of barium hexaferrite samples. X-Ray Diffraction patterns reveal the formation of hexagonal magneto-plumbite structure of BaFe12O19 with a weak intensity of secondary phase in the case of pH 4 and pH 6 samples. Interestingly disappearance of secondary phase at pH 9 sample was noticeable feature. SEM micrographs of the samples show the formation of characteristic hexagonal shape of Barium hexaferrite. Constituent elements and chemical composition were analyzed using EDX spectrum. FTIR spectra show the different metal-oxygen stretching vibration modes at 440, 546 and 596-640 cm−1 which confirms the formation of BaFe12O19. In addition pH 4 and pH 6 samples show a weak band at 770 cm−1 revealing the formation of secondary ...

Structural, electrical and magnetic properties of Ni2+ substituted cobalt nanoferrite using sol-gel method

Ni doped cobalt ferrite of chemical formula Ni(1-x)CoxFe2O4 with x values = 1, 0.5, 0 were prepared by using Poly Vinyl Alcohol (PVA) sol-gel method. The prepared samples were heat treated at 450°C for an hour and grounded to form fine powder. XRD of the powder sample confirms the formation of spinel ferrite phase. SEM and EDAX spectrum reveals the surface and chemical composition of the sample. FTIR spectra of the samples show the stretching vibration of the tetrahedral (ν1) and octahedral (ν2) bands of Fe-O bonds appearing at 600cm−1 and 424cm−1 respectively. Room temperature magnetic and electrical studies were done using VSM and LCZ meter to analyze their property respectively.