<abstract xmlns="http://www.w3.org/1999/xhtml">Zn1-xNixO aerogel nanopowders with nickel concentration in the range of 0.05 ≤ x ≤ 0.25, were synthesized by the sol-gel processing technique and post-annealed in air at 500 °C. Structural, vibrational, thermal and magnetic properties of the as-prepared and annealed Zn1-xNixO powdered samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman scattering, thermal gravimetric analysis (TGA) and electron paramagnetic resonance (EPR) spectroscopy. In addition to the ZnNiO phase, XRD analysis revealed the formation of a secondary NiO phase when the Ni content was greater than or equal to 10 %. The TEM images confirm that the particle size is in the range of 20 nm to 40 nm, in accordance with XRD results, and the particles are well dispersed. Raman scattering measurements confirm the wurtzite structure of the synthesized Zn1-xNixO nanopowders and show that intrinsic host-lattice defects are activated when Ni2+ ions are substituted to the Zn sites. Room temperature ferromagnetic order was observed in all of the samples and was strongly dependent on the Ni content and thermal annealing. These results indicate that the observed room temperature ferromagnetism in ZnNiO may be attributed to the substitutional incorporation of Ni at Zn sites. </abstract>

Zn1-xNixO aerogel nanopowders with nickel concentration in the range of 0.05 ≤ x ≤ 0.25, were synthesized by the sol-gel processing technique and post-annealed in air at 500 °C. Structural, vibrational, thermal and magnetic properties of the as-prepared and annealed Zn1-xNixO powdered samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman scattering, thermal gravimetric analysis (TGA) and electron paramagnetic resonance (EPR) spectroscopy. In addition to the ZnNiO phase, XRD analysis revealed the formation of a secondary NiO phase when the Ni content was greater than or equal to 10 %. The TEM images confirm that the particle size is in the range of 20 nm to 40 nm, in accordance with XRD results, and the particles are well dispersed. Raman scattering measurements confirm the wurtzite structure of the synthesized Zn1-xNixO nanopowders and show that intrinsic host-lattice defects are activated when Ni2+ ions are substituted to the Zn sites. Room temperature ferromagnetic order was observed in all of the samples and was strongly dependent on the Ni content and thermal annealing. These results indicate that the observed room temperature ferromagnetism in ZnNiO may be attributed to the substitutional incorporation of Ni at Zn sites.

Annealing and Ni content effects on EPR and structural properties of Zn1–xNixO aerogel nanoparticles

Materials Science-Poland

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Annealing and Ni content effects on EPR and structural properties of ZnNiO aerogel nanoparticles

Zn1-xNixO aerogel nanopowders with nickel concentration in the range of 0.05 ≤ x ≤ 0.25, were synthesized by the sol-gel processing technique and post-annealed...

Annealing and Ni content effects on EPR and structural properties of Zn_1–xNi_xO aerogel nanoparticles

Published Online: Oct 31, 2017

Page range: 454 - 462

Received: Feb 23, 2016

Accepted: Jun 26, 2017

DOI: https://doi.org/10.1515/msp-2017-0062

Keywords
Ni-doped ZnO, nanoparticles, TEM, XRD, Raman scattering, EPR spectroscopy

© 2017

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Annealing and Ni content effects on EPR and structural properties of Zn1–xNixO aerogel nanoparticles

Published Online: Oct 31, 2017

Page range: 454 - 462

Received: Feb 23, 2016

Accepted: Jun 26, 2017

DOI: https://doi.org/10.1515/msp-2017-0062

KeywordsNi-doped ZnO, nanoparticles, TEM, XRD, Raman scattering, EPR spectroscopy

© 2017

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Annealing and Ni content effects on EPR and structural properties of Zn_1–xNi_xO aerogel nanoparticles

Keywords
Ni-doped ZnO, nanoparticles, TEM, XRD, Raman scattering, EPR spectroscopy