Self-assembly and magnetic properties of cobalt nanoparticles

Abstract

Two- and three-dimensional superlattices of passivated cobalt nanoparticles were formed by a self-assembly technique. The size and stabilization of the cobalt nanoparticles are controlled by using the combination of oleic acid and triphenylphosphine. The cobalt nanoparticles are stable for at least 90 days without oxidation at room temperature under ambient conditions. The magnetic properties of the cobalt nanoparticles in different forms are compared, which provides helpful information on the magnetostatic interaction of the nanoparticles.

Phase transition from the ferromagnetic to superparamagnetic with a loop shift in 5-nm nickel particles

“…Additionally, many new phenomena and properties are expected to appear in nanoparticles of the size less than 10 nm by reason that the particle size is smaller than the dimension of atomic or ionic diffusion length, electronic elastic and inelastic mean free path length, and the magnetic domain size [3][4][5]. Recently, a few more researches focus on the magnetic nanoparticles related to the application of ultimate density of magnetic information storage [6,7].…”

Hetergeneous-nucleation synthesis of monodisperse ε-cobalt nanoparticles using palladium seeds

“…The magnetic properties of the bimetallic Pd-Co NPs were compared with those of the homogenously nucleated e-Co NPs in our earlier work [6], which sizes can be controlled from 5 nm to 9 nm by adjusting the concentration ratio of reagents to surfactants. Measurements of isolated NPs properties were carried out on the cobalt NPs powder compacted into a capsule by using a Quantum Design MPMS-5 SQUID.…”

The Controlled Growth of Long AlN Nanorods and In-situ Investigation on Their Field Emission Properties

“…Fe 3 O 4 nanoparticles were synthesized as the catalysts of the AlN nanocones, nanorods and nanocraters by high temperature solution phase reaction (Yang et al, 2003;He et al, 2001), which were spread over the substrate. The CVD system has been described in our recent works (Liu et al, , 2005(Liu et al, , 2008Cao et al, 2003), as shown in Fig.1.…”