Magnetic properties of Co2C and Co3C nanoparticles and their assemblies

Abstract

Nano-composite material consisting of Co 2 C and Co 3 C nanoparticles has recently been shown to exhibit unusually large coercivities and energy products. Experimental studies that can delineate the properties of individual phases have been undertaken and provide information on how the coercivities and the energy product change with the size and composition of the nanoparticles. The studies indicate that while both phases are magnetic, the Co 3 C has higher magnetization and coercivity compared to Co 2 C. Through first principles electronic structure studies using a GGAþU functional, we provide insight on the role of C intercalation on enhancing the magnetic anisotropy of the individual phases. V

CoxC nanorod magnets: Highly magnetocrystalline anisotropy with lower Curie temperature for potential applications

“…Any residual solvent or unreacted salts were removed by washing 3 times with ethanol. Further details are described elsewhere [10,11].…”

“…Recently a new class of hard magnetic materials based on nanocrystalline Co x C(x ¼2 or 3) have shown promise for these alternative energy applications. Cobalt carbide nanoparticles synthesized using a modified polyol process and described elsewhere [10][11][12]. These particles show a narrow size distribution, stability against oxidation, larger magnetocrystalline anisotropy, and larger coercivity.…”

Stable magnetic order and charge induced rotation of magnetization in nano-clusters

“…However, recent studies have indicated that the transition metal based nanoparticles where the transition metal layers are separated by carbon (C) layers, exhibit large MAE. 31,32 We have also shown recently that small Co clusters diluted with C undergo significant enhancement in MAE. 33 Such enhancement of MAE in transition metal carbide (TMC) results due to the mixing of p states of C with d states of transition metal.…”

Transition Metal (Fe, Co and Ni) Carbide and Nitride Nanomaterials: Structure, Chemical Synthesis and Applications

“…To investigate the unique evolution of the magnetic moment with a changing amount of carbon atoms incorporated into the metallic cobalt structure, Carpenter et al reported Co 2 C and Co 3 C nanocomposites both theoretically and experimentally. The authors showed that the addition of carbon atoms was critical to control the anisotropy of individual phases …”