Structural and magnetic characterization of Co-Cu nanoparticles prepared by arc-

2020-01-23 01:14:05

The Co magnetic nanoparticles oxide

责任者: Cai-yin You;Yang, Z.Q.;Xiao, Q.F.;Skorvanek, I.;Kovac, J.;Li, Z.J.;Liu, W.;Zhang, Z.D. 单位: Shenyang Nat. Lab. for Mater. Sci., Chinese Acad. of Sci., Shenyang, China 来源出处: European Physical Journal, Applied Physics(Eur. Phys. J. Appl. Phys. (France)),2004/10/,28(1):73-7 摘要: The structure and magnetic properties of the nanoparticles of immiscible system Co20Cu80 prepared by means of arc-discharge, have been studied in detail. The diameters of the particles are about 20 ~ 30 nm and a core/shell structure forms. The cores are Co-Cu solutions, which show some small Co precipitates, encapsulated with a shell of copper oxide or cobalt oxide as observed by means of high-resolution transmission electron microscope (HRTEM) and energy dispersive X-ray (EDS). The loop shift in the hysteresis loop indicates the existence of the exchange bias between ferromagnetic and antiferromagnetic components at low temperatures. A block temperature about 180 K has been observed for as-deposited nanoparticles. For the annealed nanoparticles, the thermal magnetization at low temperatures is satisfied with Blochs law 关键词: annealing;antiferromagnetic materials;cobalt alloys;copper alloys;crystal microstructure;encapsulation;ferromagnetic materials;magnetic hysteresis;magnetic particles;materials preparation;nanoparticles;solubility;transmission electron microscopy;X-ray chemical analysis;X-ray diffraction;arc-discharge preparation;nanoparticles;magnetic characterization;structural characterization;immiscible system;particle diameter;core/shell structure;Co precipitates;encapsulation;copper oxide;cobalt oxide;high-resolution transmission electron microscope;HRTEM;energy dispersive X-ray;EDS;hysteresis loop;exchange bias;ferromagnetic components;antiferromagnetic components;block temperature;annealing;thermal magnetization;Bloch law;20 to 30 nm;Co20Cu80