- Turkish Journal of Chemistry
- Vol: 42 Issue: 5
- Phase transition of chemically synthesized FePt nanoparticles under high pressure
Phase transition of chemically synthesized FePt nanoparticles under high pressure
Authors : Telem Şimşek, Özgür Karci, Şadan Özcan
Pages : 1217-1223
View : 9 | Download : 4
Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :We present the results of a study related to phase transformation of chemically synthesized FePt nanoparticles under high pressure from face-centered cubic into face-centered tetragonal structure. As-synthesized nanoparticles are around 4.5 nm and show superparamagnetic behavior at 300 K. After annealing under 60 bar pressure of hydrogen at 400 ∘ " role="presentation"> ∘ ∘ ^{\circ} C for 2 h, nanoparticles exhibit strong ferromagnetic behavior with 5391 Oe coercivity. Results show that high-pressure annealing lowers the decomposition temperature of the surfactants surrounding nanoparticles and partially hinders agglomeration arising from heat treatment. The promising ferromagnetic properties of the FePt nanoparticles after annealing under high pressure make them suitable for ultrahigh-density memory devices.Keywords : Chemical method, iron-platinum nanoparticles, magnetic data storage, phase transition