Evolution of High Coercivity in CoPt Nanoparticles Through Nitrogen Assisted Annealing (original) (raw)

Abstract

The presence of H 2 along with an inert gas during annealing was considered as a prerequisite in achieving high coercivity in alloys such as FePt and CoPt nanoparticles synthesized through chemical methods. CoPt nanoparticles were synthesized using a one-step polyol process without using any surfactant and annealed at various temperatures in N 2 atmosphere. The magnetic properties of Co 40 Pt 60 sample annealed at 700 o C in N 2 atmosphere showed a room temperature coercivity of 8.4 kOe. The magnetic interactions present in the samples were studied using δM measurements. The evolution of high coercivity in the samples annealed at 700 o C showed that N 2 is a cheaper alternative to the existing reducing gas mixture.

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