Reduction of ordering temperature in substituted FePtNi nanoparticles formed by chemical synthesis

Author

Wang, H.L. ; Huang, Y. ; Zhang, Y. ; Unruh, K.M. ; Hadjipanayis, G.C. ; Weller, D. ; Simopoulos, T.

Author_Institution

Dept. of Phys., Delaware Univ., Newark, DE, USA

fYear

2005

fDate

4-8 April 2005

Firstpage

875

Lastpage

876

Abstract

In this paper, we used Ni substitution for Pt to reduce the transformation temperature of the FePt alloys where FePtNi nanoparticles were fabricated by chemical synthesis. M vs T data showed a blocking temperature at around 35 K, consistent with the tiny size (2-3 nm) of the particles. DSC data indicate a structural transformation from fcc to fct at a temperature about 70°C lower in Fe₆₀(Pt_0.7Ni_0.3)₄₀ than in Fe₅₈Pt₄₂ as confirmed by XRD and hysteresis loop measurements. Mossbauer spectra and relation of coercivity with annealing temperature and time were also presented.

Keywords

Mossbauer effect; X-ray diffraction; annealing; coercive force; differential scanning calorimetry; ferromagnetic materials; iron alloys; magnetic hysteresis; nanoparticles; nickel alloys; platinum alloys; solid-state phase transformations; 2 to 3 nm; DSC; FePtNi; Mossbauer spectra; XRD; annealing; blocking temperature; chemical synthesis; coercivity; hysteresis loop; nanoparticles; ordering temperature reduction; structural transformation; substitution; transformation temperature; Annealing; Chemicals; Coercive force; Hysteresis; Iron; Nanoparticles; Nickel alloys; Platinum alloys; Temperature; X-ray scattering;

fLanguage

English

Publisher

ieee

Conference_Titel

Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International

Print_ISBN

0-7803-9009-1

Type

conf

DOI

10.1109/INTMAG.2005.1463866

Filename

1463866