TY - JOUR
T1 - Investigations on magnetic properties and structure for carbon encapsulated nanoparticles of Fe, Co, Ni
AU - Sun, Xiangcheng
AU - Gutierrez, A.
AU - Yacaman, M. Jose
AU - Dong, Xinglong
AU - Jin, Shouri
N1 - Funding Information:
The present work is financially supported by CONACyT projects through ‘Quantum Colliods’ in Mexico. The authors are grateful to Mr. R. Reglero for TEM images preparation and Ms. Thelma at XRD analysis.
PY - 2000/6/30
Y1 - 2000/6/30
N2 - In the present work, experiments aim at the encapsulation of foreign materials within hollow graphitic cage have been carried out for iron group metals (Fe, Co, Ni) using a modified arc-discharge (carbon arc) reactor. HRTEM (high resolution transmission electron miscroscope), and XRD (X-ray diffractometer) studies, for three carbon encapsulated materials, showing nanoparticles of both a metallic phase (α-Fe, γ-Fe; hcp-Co, fcc-Co; fcc-Ni) and also a carbide phase (M3C, M=Fe, Co, Ni) are encapsulated in graphitic carbon. The magnetic measurement for the three as-made nanoparticles, indicating that the values of saturation magnetic moment of three nanoparticle are 37.6, 55.5 and 15.7% of the bulk ferromagnetic elements counterparts, respectively. The different comparison values (Mr/Ms) of remanent magnetization (Mr) and saturation magnetization (Ms) suggest, the encapsulated Fe and Co nanoparticles are shown to be ferromagnetic with a ratio of remnant to saturation magnetization Mr/Ms~0.3; whereas, the encapsulated Ni nanoparticles exhibits superparamagnetic behavior at room temperature.
AB - In the present work, experiments aim at the encapsulation of foreign materials within hollow graphitic cage have been carried out for iron group metals (Fe, Co, Ni) using a modified arc-discharge (carbon arc) reactor. HRTEM (high resolution transmission electron miscroscope), and XRD (X-ray diffractometer) studies, for three carbon encapsulated materials, showing nanoparticles of both a metallic phase (α-Fe, γ-Fe; hcp-Co, fcc-Co; fcc-Ni) and also a carbide phase (M3C, M=Fe, Co, Ni) are encapsulated in graphitic carbon. The magnetic measurement for the three as-made nanoparticles, indicating that the values of saturation magnetic moment of three nanoparticle are 37.6, 55.5 and 15.7% of the bulk ferromagnetic elements counterparts, respectively. The different comparison values (Mr/Ms) of remanent magnetization (Mr) and saturation magnetization (Ms) suggest, the encapsulated Fe and Co nanoparticles are shown to be ferromagnetic with a ratio of remnant to saturation magnetization Mr/Ms~0.3; whereas, the encapsulated Ni nanoparticles exhibits superparamagnetic behavior at room temperature.
KW - Carbon encapsulated nanoparticles
KW - Magnetic properities
KW - Superparamagnetic
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U2 - 10.1016/S0921-5093(00)00628-6
DO - 10.1016/S0921-5093(00)00628-6
M3 - Article
AN - SCOPUS:0000287540
SN - 0921-5093
VL - 286
SP - 157
EP - 160
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
IS - 1
ER -