Reducing the ordering temperature of CoPt nanoparticles by B additive

Journal Article · Thu Aug 07 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4892487· OSTI ID:22314556

Khemjeen, Yutthaya ^[1]; Pinitsoontorn, Supree; Chompoosor, Apiwat ^[2]; Maensiri, Santi ^[3]

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1. Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand)
2. Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand)
3. School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand)

We reported the effect of boron addition on magnetic properties and structure of CoPt nanoparticles prepared by a polyol method. The magnetic property measurement showed that the CoPt-B sample exhibited a much larger coercivity compared to the sample without B additive at the same annealing temperature. Transmission electron microscopy and energy dispersive X-ray spectroscopy revealed that the average particle size was about 2 nm for the as-synthesized sample with the ratio of Co and Pt close to 1:1. After annealing, the particle sizes increased but the composition was maintained. The phase transformation of the nanoparticles versus temperature was investigated using a combination of X-ray diffraction and in-situ X-ray absorption analysis. It was shown that the phase transition temperature at which the nanoparticles change from the disordered A1 phase to the ordered L1{sub 0} phase occurs at temperature of 600 °C. We concluded that boron additives could reduce the ordering temperature of CoPt of about 100 °C.

• OSTI ID: 22314556
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
ADDITIVES
ANNEALING
BORON ADDITIONS
COERCIVE FORCE
COMPARATIVE EVALUATIONS
MAGNETIC PROPERTIES
NANOPARTICLES
PARTICLE SIZE
PHASE TRANSFORMATIONS
TRANSITION TEMPERATURE
TRANSMISSION ELECTRON MICROSCOPY
X RADIATION
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY