Oxygen vacancy induced by La and Fe into ZnO nanoparticles to modify ferromagnetic ordering

Journal Article · Sun May 15 00:00:00 EDT 2016 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2016.02.015· OSTI ID:22584073

Verma, Kuldeep Chand, E-mail: [e-mail] ^[1]; Kotnala, R.K., E-mail: [e-mail] ^[2]

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1. Centre of Advanced Study in Physics, Department of Physics, Panjab University, Chandigarh 160 014 (India)
2. CSIR-National Physical Laboratory, New Delhi 110012 (India)

We reported long-range ferromagnetic interactions in La doped Zn{sub 0.95}Fe{sub 0.05}O nanoparticles that mediated through lattice defects or vacancies. Zn{sub 0.92}Fe{sub 0.05}La{sub 0.03}O (ZFLaO53) nanoparticles were synthesized by a sol–gel process. X-ray fluorescence spectrum of ZFLaO53 detects the weight percentage of Zn, Fe, La and O. X-ray diffraction shows the hexagonal Wurtzite ZnO phase. The Rietveld refinement has been used to calculate the lattice parameters and the position of Zn, Fe, La and O atoms in the Wurtzite unit cell. The average size of ZFLaO53 nanoparticles is 99 nm. The agglomeration type product due to OH ions with La results into ZnO nanoparticles than nanorods that found in pure ZnO and Zn{sub 0.95}Fe{sub 0.05}O sample. The effect of doping concentration to induce Wurtzite ZnO structure and lattice defects has been analyzed by Raman active vibrational modes. Photoluminescence spectra show an abnormal emission in both UV and visible region, and a blue shift at near band edge is formed with doping. The room temperature magnetic measurement result into weak ferromagnetism but pure ZnO is diamagnetic. However, the temperature dependent magnetic measurement using zero-field and field cooling at dc magnetizing field 500 Oe induces long-range ferromagnetic ordering. It results into antiferromagnetic Neel temperature of ZFLaO53 at around 42 K. The magnetic hysteresis is also measured at 200, 100, 50 and 10 K measurement that indicate enhancement in ferromagnetism at low temperature. Overall, the La doping into Zn{sub 0.95}Fe{sub 0.05}O results into enhanced antiferromagnetic interaction as well as lattice defects/vacancies. The role of the oxygen vacancy as the dominant defects in doped ZnO must form Bound magnetic polarons has been described. - Graphical abstract: The long-range ferromagnetic order in Zn{sub 0.92}Fe{sub 0.05}La{sub 0.03}O nanoparticles at low temperature measurements involves oxygen vacancy as the medium of magnetic interactions. - Highlights: • The La and Fe doping into ZnO nanoparticles induce defects in terms of oxygen vacancy. • The La ions in Fe substituted ZnO formed nanoparticles than nanorods. • Antiferromagnetic interactions are observed at room temperature magnetic measurement. • Rietveld analysis evaluated structural deformation in the Wurtzite ZnO lattice.

• OSTI ID: 22584073
• Journal Information: Journal of Solid State Chemistry, Vol. 237; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANTIFERROMAGNETISM
DOPED MATERIALS
FERROMAGNETISM
FLUORESCENCE
FLUORESCENCE SPECTROSCOPY
INTERACTIONS
LANTHANUM IONS
NANOPARTICLES
NEEL TEMPERATURE
OXYGEN
PHOTOLUMINESCENCE
SOLS
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
VACANCIES
X RADIATION
X-RAY DIFFRACTION
ZINC OXIDES