Size-Dependent Magnetic Properties of PtMn Nanoparticles

Author

Ho, Chien-Hsin ; Lai, Chih-Huang

Author_Institution

Dept. of Mater. Sci. & Eng., Nat. Tsing Hua Univ.

Volume

42

Issue

10

fYear

2006

Firstpage

3069

Lastpage

3071

Abstract

PtMn nanoparticles have been synthesized by chemical methods. The as-synthesized PtMn nanoparticles show superparamagnetic behavior at room temperature and ferromagnetic behavior at 5 K due to the uncompensated surface spins originating from the finite size effect. Different PtMn sizes were obtained after various temperature annealing processes. The exchange bias and vertical loop shift of PtMn nanoparticles were observed at 5 K in field cooling process and were ascribed to the exchange coupling of ferromagnetic surface spins and the antiferromagnetic core. It was found that the coercivity and exchange bias field were strongly related to the particle size

Keywords

antiferromagnetic materials; coercive force; ferromagnetism; magnetic annealing; magnetic particles; nanoparticles; particle size; platinum alloys; superparamagnetism; 5 K; PtMn; PtMn nanoparticles; antiferromagnetic core; chemical methods; exchange bias; exchange coupling; ferromagnetic surface spins; field cooling process; particle size; size-dependent magnetic properties; superparamagnetic behavior; temperature annealing processes; vertical loop shift; Annealing; Antiferromagnetic materials; Chemicals; Coercive force; Cooling; Magnetic field measurement; Magnetic hysteresis; Magnetic properties; Nanoparticles; Temperature; Exchange bias; PtMn nanoparticles; size dependent; vertical loop shift;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2006.880110

Filename

1704529