Journal of Nanoparticle Research

, Volume 13, Issue 1, pp 245–255

Morphology and magnetic properties of island-like Co and Ni films obtained by de-wetting

  • P. Tiberto
  • S. Gupta
  • S. Bianco
  • F. Celegato
  • P. Martino
  • A. Chiolerio
  • A. Tagliaferro
  • P. Allia
Research Paper

DOI: 10.1007/s11051-010-0023-2

Cite this article as:
Tiberto, P., Gupta, S., Bianco, S. et al. J Nanopart Res (2011) 13: 245. doi:10.1007/s11051-010-0023-2

Abstract

The morphological, structural, and magnetic properties of Co and Ni films of different thicknesses grown by RF sputtering on a Si–SiO substrate and submitted to controlled diffusion of atoms on the substrate (de-wetting) are studied through X-ray diffraction (XRD), atomic force microscopy, X-ray photoelectron spectroscopy, and alternating-gradient magnetometry. For both metals, de-wetting treatment leads to the growth of non-percolating, metallic nanoislands characterized by a distribution of sizes and aspect ratios. XRD spectra reveal a polycrystalline multi-component structure evolving by effect of de-wetting and directly affecting the magnetic properties of films. The magnetic response after de-wetting is consistent with the formation of a nanogranular magnetic phase characterized by a complex, thickness-dependent magnetic behavior originating from the simultaneous presence of superparamagnetic and blocked-particle contributions. At intermediate film thickness (around 10 nm), a notable enhancement in magnetic coercivity is observed for both metals with respect to the values measured in precursor films and in their bulk counterparts.

Keywords

Magnetic nanoparticlesMagnetic thin filmsDe-wetting techniqueCoercive field

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • P. Tiberto
    • 1
  • S. Gupta
    • 2
  • S. Bianco
    • 3
  • F. Celegato
    • 1
  • P. Martino
    • 2
  • A. Chiolerio
    • 2
  • A. Tagliaferro
    • 2
  • P. Allia
    • 2
  1. 1.Electromagnetism DivisionINRIMTurinItaly
  2. 2.Politecnico di Torino, DISMIC and DIFISTurinItaly
  3. 3.Italian Institute of Technology—IIT@POLITO, Center for Space Human RoboticsTurinItaly