Magnetic-field–induced spontaneous pattern formation in aerosol-particle deposits
FR 7.3 Technische Physik, Universität des
Saarlandes - 66041 Saarbrücken, Germany
Accepted: 26 August 2002
Magnetic nanometer-sized crystallites dissolved in an aerosol have been condensed on a substrate in the presence of a homogeneous magnetic field. Dipolar interaction favours chain formation, which on further growth leads to the self-organized formation of nanoparticle chain arrays that spontaneously undergo structural instabilities. When a critical chain length is exceeded, spontaneous formation of regular patterns is observed, similar to the Rosensweig instability in ferrofluids. We present a phenomenological stability analysis enabling to predict the magnetic-field dependence of the modulation wavelength of the observed hexagonal patterns.
PACS: 61.46.+w – Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals / 75.75.+a – Magnetic properties of nanostructures / 05.65.+b – Self-organized systems
© EDP Sciences, 2002