Magnetic field dependent small-angle neutron scattering on a Co nanorod array: evidence for intraparticle spin...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Cobalt nanorod arrays exhibit unique structural and magnetic properties.
• Understanding these properties is crucial for advanced magnetic applications.

Purpose of the Study:

• To investigate the structural and magnetic characteristics of cobalt nanorod arrays.
• To analyze the magnetic field dependence of small-angle neutron scattering (SANS).

Main Methods:

• Utilized magnetic field-dependent small-angle neutron scattering (SANS).
• Measured unpolarized SANS cross-section in perpendicular and parallel geometries.
• Separated nuclear and magnetic SANS without sector-averaging.

Main Results:

• Structural parameters (rod radius, center-to-center distance) from SANS align with electron microscopy.
• Observed significant field dependence of magnetic SANS between saturation and coercive field.
• Conventional models failed to explain the observed field dependence.

Conclusions:

• The study provides accurate structural parameters for cobalt nanorods.
• Intradomain spin misalignment, influenced by anisotropies and stray fields, is proposed as the cause of strong magnetic SANS field dependence.
• This finding offers new insights into the magnetic behavior of nanorod arrays.