Title :
Size-dependent Magnetic Properties of PtMn Nanoparticles
Author :
Ho, C. ; Lai, C.
Author_Institution :
Nat. Tsing Hua Univ., Hsinchu
Abstract :
In this study, PtMn nanoparticles were synthesized via a chemical method. After post-annealing at the temperature range of 500~700degC, different grain sizes were obtained. It was found the coercivity, measured at 5 K, decreased with increasing grain size. The exchange-bias was also observed at 5 K under a field-cooling process. The particle size and composition of as-synthesized PtMn nanoparticles were measured by TEM and EDS, respectively. The crystalline structures of as-synthesized and post-annealed samples were investigated by X-ray diffraction (XRD). Magnetic properties were measured by a SQUID magnetometer after cooling the sample to 5 K in zero-field (ZFC) or in an applied field of 1 T (FC). The as-synthesized PtMn nanoparticles show superparamagnetic behavior at room temperature.
Keywords :
X-ray diffraction; annealing; antiferromagnetic materials; coercive force; crystal structure; grain size; manganese alloys; nanoparticles; nanotechnology; platinum alloys; transmission electron microscopy; EDS; PtMn; SQUID magnetometer; TEM; X-ray diffraction; XRD; antiferromagnetic nanoparticles; chemical method; coercivity; exchange-bias; field-cooling process; grain sizes; magnetic flux density 1 tesla; particle size; post-annealing; size-dependent magnetic properties; superparamagnetic behavior; temperature 293 K to 298 K; temperature 5 K; temperature 500 C to 700 C; Chemicals; Coercive force; Crystallization; Grain size; Magnetic field measurement; Magnetic properties; Nanoparticles; Particle measurements; Size measurement; Temperature distribution;
Conference_Titel :
Magnetics Conference, 2006. INTERMAG 2006. IEEE International
Conference_Location :
San Diego, CA
Print_ISBN :
1-4244-1479-2
DOI :
10.1109/INTMAG.2006.376192
