新型碳纳米管磁性复合材料的制备及磁性能

SYNTHESIS AND MAGNETIC PROPERTIES OF NOVEL CARBON NANOTUBES MAGNETIC COMPOSITES

采用水热–沉淀法制备了ZnFe2O4包覆碳纳米管(carbon nanotubes,CNTs)磁性复合材料。采用X射线衍射、扫描电镜、透射电镜、Mssbauer谱仪和振动样品磁强计等仪器表征制备样品的结构与性能。200℃是制备纳米ZnFe2O4包覆CNTs磁性复合材料的较好的反应条件,温度过高或过低都生成较多的γ-Fe2O3。包覆在CNTs上的ZnFe2O4纳米粒子为球形,粒径为13～20nm。Mssbauer谱结果表明:大部分ZnFe2O4纳米粒子表现出超顺磁性,少量表现出铁磁性。磁滞回线结果表明:复合材料的矫顽力值为254215.85A/m。

Novel magnetic composites of carbon nanotubes（CNTs） coated with ZnFe2O4 nanoparticles were synthesized by a precipitation-hydrothermal method. The composites were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, Mossbauer spectrum（MS）, and vibrating sample magnetometry. A temperature of about 200℃ was identified to be an appropriate reactive condition to obtain CNTs coated with ZnFe2O4. It is concluded that more γ-Fe2O3 existed in composites when the temperature is higher or lower than 200℃. The ZnFe2O4 nanoparticles coated on surface of CNTs are round, and the size of the nanoparticles ranges from 13 nm to 20 nm. The MS results reveal that most of the ZnFe2O4 nanoparticles show superparamagnetic relaxation, and some of them exhibit ferrite magnetic relaxation. The sample demonstrates good magnetic properties with a coercive strength of 254 215.85 A/m.