Direct Investigation of Superparamagnetism in Co Nanoparticle Films

Abstract

A direct probe of superparamagnetism was used to determine the complete anisotropy energy distribution of Co nanoparticle films. The films were composed of self-assembled lattices of uniform Co nanoparticles 3 nm or 5 nm in diameter, and a variable temperature scanning-SQUID microscope was used to measure temperature-induced spontaneous magnetic noise in the samples. Accurate measurements of anisotropy energy distributions of small volume samples will be critical to magnetic optimization of nanoparticle devices and media.

4 pages, 4 figures. Submitted to Physical Review Letters

References in corpus (1)

• Magnetic Anisotropy of a Single Cobalt Nanoparticle

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