Annealing-dependent structural and magnetic properties of nickel oxide (NiO) nanoparticles in a silica matrix

Dobrica Nikolic, Matjaz Panjan, Graeme R. Blake, Marin Tadic*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

15 Citations (Scopus)

Abstract

We show that annealing at high temperatures has a significant effect on the structural and magnetic properties of NiO/SiO2 nanostructures synthesized by a sol-gel combustion method. Samples underwent heat treatments at 500 degrees C, 800 degrees C, 950 degrees C and 1100 degrees C. As compared to the 500 degrees C sample, the 800 degrees C sample showed the following magnetic properties: much higher irreversibility temperature, a significantly broadened zero-field-cooled (ZFC) magnetization maximum, a decrease of the ZFC magnetization, an increase of the coercivity, and weaker inter-particle interactions. These changes can be attributed to agglomeration of nanoparticles in part of the sample. We believe that this agglomeration can be explained by the removal of thin regions of silica that separate nanoparticles in close proximity during the annealing process at 800 degrees C. Magnetic measurements for the 1100 sample reveal both an abrupt increase in size of the NiO nanoparticles, which is confirmed by TEM and XRPD measurements, and an increase in inter-particle interaction strength. (C) 2015 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)3843-3852
Number of pages10
JournalJournal of the European Ceramic Society
Volume35
Issue number14
DOIs
Publication statusPublished - Nov-2015

Keywords

  • Nickel oxide (NiO)
  • Sol-gel combustion synthesis
  • Interparticle interactions
  • Superparamagnetism
  • AC susceptibility
  • IRON-OXIDE
  • HEMATITE NANOPARTICLES
  • ANTIFERROMAGNETIC NIO
  • BLOCKING TEMPERATURES
  • ROOM-TEMPERATURE
  • SIZE DEPENDENCE
  • BEHAVIOR
  • NANOCOMPOSITES
  • NANOSTRUCTURE
  • NANOSHEETS

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