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Title: High temperature ferromagnetism in Ni doped ZnO nanoparticles: Milling time dependence

We report on the room temperature ferromagnetism (RT FM) in the Zn{sub 1−x}Ni{sub x}O (x = 0, 0.03, and 0.05) nanoparticles (NPs) synthesized by a ball milling technique. X-ray diffraction analysis confirms the single crystalline ZnO wurtzite structure with presence of small intensity secondary phase related peak which disappear with increasing milling time for Ni doped samples. HRTEM lattice images show that the doped NPs are single crystalline with a dspacing of 2.44 Å. Energy-dispersive X-ray spectroscopy analysis confirms the presence of Ni ions in the ZnO matrix. Magnetic measurement (RT) exhibits the hysteresis loop with saturation magnetization (M{sub s}) of 1.6–2.56 (emu/g) and coercive field (H{sub c}) of 296–322 Oe. M-T measurement shows a Curie temperature of the order of 325°C for 3% Ni doped sample. Micro -Raman studies show doping/disorder induced additional modes at ∼510, 547, 572 cm{sup −1} in addition to 437 cm{sup −1} peak of pure ZnO. UV-Vis absorption spectra illustrate band gap shift due to doping. Alteration of M{sub s} value with the variation of doping concentration and milling time has been studied and discussed.
Authors:
;  [1] ;  [2]
  1. Department of Physics, Gauhati University, Guwahati- 781014 (India)
  2. Department of Physics, Indian Institute of Technology Guwahati, Guwahati -781039 (India)
Publication Date:
OSTI Identifier:
22269509
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1591; Journal Issue: 1; Conference: 58. DAE solid state physics symposium 2013, Patiala, Punjab (India), 17-21 Dec 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION SPECTRA; CONCENTRATION RATIO; CURIE POINT; DOPED MATERIALS; FERROMAGNETISM; MAGNETIZATION; MILLING; MONOCRYSTALS; NANOSTRUCTURES; NICKEL COMPOUNDS; NICKEL IONS; PARTICLES; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; TIME DEPENDENCE; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION; X-RAY SPECTROSCOPY; ZINC OXIDES