dc and high frequency magnetic properties of nanopatterned CoFe2O4 arrays fabricated using sol-gel precursors.

Nanostructures of ferromagnetic oxides having Curie temperatures above room temperature have potential for applications in memory devices and future spin-based electronic applications. In this article, we report on the dc and high frequency magnetic properties of arrays of elliptical CoFe2O4 nanopillars, covering a large area, fabricated by combined electron beam lithography, and a sol-gel based chemical route. The nanopillars were successfully fabricated on insulating oxidized silicon substrates and on epitaxial thin films of ferroelectric BiFeO3. We performed magnetic force microscopy and ferromagnetic resonance spectroscopy on the arrays to probe their magnetic properties. Due to the possible existence of dominant pinning sites, the CoFe2O4 nanopillars are not single-domain even at nanometer size scales. [ABSTRACT FROM AUTHOR]