Ferromagnetic and spin-glass behaviour of nanosized oriented pyrolytic graphite in Pb-C nanocomposites
Ferromagnetic and spin-glass behaviour of nanosized oriented pyrolytic graphite in Pb-C nanocomposites
复制标题
Pb-C 纳米复合材料中纳米定向热解石墨的铁磁和自旋玻璃行为
DOI：
10.1088/0022-3727/41/11/115005
复制
发表时间：
2008-06-07
影响因子：
3.4
通讯作者：
Zhang, Zhidong
中科院分区：
文献类型：
--
作者：
Li, Da;Han, Zheng;Zhang, Zhidong
Pb-C nanocomposites consisting of pyrolytic carbon nanospheres and Pb nanoparticles were produced by discharging a mixture of Pb and graphite powders in an ethanol and Ar atmosphere. Raman spectrum and x-ray photoelectron spectroscopy indicated that the carbons in the Pb-C nanocomposites are in both ordered and disordered forms. The Pb atoms in the Pb-C nanocomposites were removed by the treatment of a 65% HNO3 solution to form carbon nanocomposites in order to have a comparison. X-ray diffraction data and magnetic measurements revealed the magnetism of the nanosized pyrolytic carbon with different degrees of crystallization, in which disordered carbon with a (0 0 2) interlayer spacing of 0.342 nm is diamagnetic, while the oriented pyrolytic graphite with a spacing of 0.337 nm shows ferromagnetism. The saturation magnetization of highly oriented pyrolytic graphite (HOPG) nanospheres is enhanced by about two orders of magnitude, compared with that of bulk HOPG. Spin-glass behaviour of HOPG nanospheres may be caused by complex competing interactions between magnetic moments in nanosized HOPG.
