Size analysis and magnetic structure of nickel nanoparticles

D. X. Chen, O. Pascu, A. Roig, A. Sanchez

Research output: Contribution to journalArticleResearchpeer-review

22 Citations (Scopus)

Abstract

The size distribution of an assembly of fcc nickel nanoparticles is studied by measuring the temperature dependent magnetization curves fitted by a uniform model and a coreshell model, both based on the Langevin function for superparamagnetism with a log-normal particle volume distribution. The uniform model fits lead to a spontaneous magnetization Ms much smaller than the Ms for bulk nickel and to particle sizes larger than the ones evaluated by transmission electron microscopy; the coreshell model fits can result in a correct size distribution but the Ms in the core becomes significantly greater than the Ms for bulk nickel. It is concluded that there is a coreshell magnetic structure in nickel particles. Although the enhanced Ms in the core may be related to the narrowing of the energy bands of 3d electrons in small fcc nickel particles, the modeling values of Ms are over large compared with previous calculations on nickel clusters of different structures, which implies possible existence of an exchange interaction between the core and the shell, which is not considered in the simple coreshell model. © 2010 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)3834-3840
JournalJournal of Magnetism and Magnetic Materials
Volume322
Issue number24
DOIs
Publication statusPublished - 1 Dec 2010

Keywords

  • Coreshell model
  • Magnetization curve
  • Metallic ferromagnetic nanoparticle
  • Particle size determination

Fingerprint Dive into the research topics of 'Size analysis and magnetic structure of nickel nanoparticles'. Together they form a unique fingerprint.

  • Cite this