Improvement In Ferromagnetism Of NiFe2O4 nanoparticles With Zn Doping
Sukhdeep Singh, Manpreet Singh, N.K. Ralhan, R.K. Kotnala and Kuldeep Chand Verma
Volume 3, Issue 6, Page 504-506 | DOI: 10.5185/amlett.2012.icnano.226
Keywords: Nanoparticles; ferromagnetism; TEM.
Structural, microstructural, infrared analysis and magnetic properties of Ni1-x ZnxFe2O4 (NZ) [x = 0.30 (NZ30), 0.35 (NZ35) and 0.40 (NZ40)] nanoferrites have been thoroughly studied. These NZ nanoferrites were synthesized by chemical combustion route and annealed at 500 oC for 5h. Fourier transform infrared (FTIR) spectra of these samples were used to identify formation of Ni-Zn spinel ferrites. These FTIR results show two characteristic absorption bands corresponding to M-O intrinsic stretching vibrations at the tetrahedral site and octahedral-metal stretching around 570-550 cm-1 and 450-435 cm-1, respectively. The X-ray diffraction shows the polycrystalline with spinel phase of these ferrites. The value of lattice constant a(Å) = 8.370, 8.371 and 8.380 respectively, for NZ30, NZ35 and NZ40 which are consistent with that reported for pure NiFe2O4. The average particles size is measured using Debye-Scherer’s relation which lies in the range of 25-65 nm. Transmission electron microscopy measured average grain size is 26, 41 and 66 nm, respectively for NZ30, NZ35 and NZ40 samples. The magnetic measurement shows saturation magnetization (Ms) of 67.63, 74.97, 80.63 emu/g, remanent magnetization (Mr) 20.01, 25.30, 25.30 emu/g and coercive field (Hc) 154.12, 154.13, 154.11 Oe, respectively for NZ30, NZ35 and NZ40. Highest saturation magnetization with Zn doping has been observed in the case of NZ40.