Size and structure control of magnetic nanoparticles by using a modified polyol process

Abstract

Synthesis strategies for the size and structure controlled Ni, Co, and FePt nanoparticles by manipulating the reaction kinetics of the polyol process are reported. In the case of Ni, particle size varied from a few micron to a few tens of nanometer, and the structure from fcc to a mixture of fcc and hcp was realized. The Co particle structure has been changed from a mixture of fcc and hcp at micron size range, to the fcc dominant mixture of fcc and hcp in the submicron size range, then to ε- and hcp-Co and finally to hcp-Co in the nanosize range. In the case of FePt, particles had fcc and fct phases with 5–10 nm in diameter. The magnetic properties of these particles are also reported.