Applied Physics A

, Volume 111, Issue 3, pp 853-859

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Co x Ag1−x core–shell nanoparticles: magnetic and magneto-optical studies

  • B. Kalska-SzostkoAffiliated withInstitute of Chemistry, University of Bialystok Email author 
  • , M. HilgendorffAffiliated withInstitut für Experimentalphysik, Freie Universität Berlin
  • , M. GiersigAffiliated withInstitut für Experimentalphysik, Freie Universität Berlin
  • , P. FumagalliAffiliated withInstitut für Experimentalphysik, Freie Universität Berlin


The magneto-optical properties of 14-nm Co x Ag1−x core–shell nanoparticles (x=0.7, 0.8, and 0.35) deposited on different substrates are investigated at room temperature in the photon-energy range from 0.8 to 4.8 eV. Particles with low Ag content show spectra very similar to pure Co nanoparticles while particles with high Ag content have totally different features, where the Ag plasma edge dominates the spectra. The spectral features of the polar Kerr rotation depend on particle composition. The ageing process and development of an oxide layer influence the particles’ core–shell structures and magnetization curves. Co-rich particles exhibit lower resistance to the oxidation process as compared to Ag-rich ones. The quality of the nanoparticles was checked by transmission electron microscopy in respect of time scale.