气相爆轰法合成超细碳包铁纳米颗粒

Synthesis of Ultrafine Carbon-encapsulated Iron by Gaseous Detonation Method

以气化五羰基铁为铁源,采用乙炔为可燃气氛,用气相爆轰法成功合成了超细碳包铁纳米颗粒。利用TEM和XRD对合成产物进行分析表明,爆轰产物是由碳壳层、α-Fe和γ-Fe组成的球状包覆型结构,产物分散性好,颗粒大小均匀、形态规则的球形超细纳米碳包铁颗粒,铁核的平均粒径为4.5 nm; Raman光谱分析也证实该纳米粒子表面由为石墨和无定型碳构成包覆。进一步将该纳米碳包铁颗粒在低真空温度673 K下进行热处理发现,铁核颗粒尺寸略有长大,XRD谱线上γ-Fe相消失,转化为α-Fe相,热处理后磁饱和强度提高1倍以上。

With pentacarbonyl iron as iron source and acetylene as carbon source, ultrafine carbon-encapsulated iron(Fe@C) nanoparticles were synthesized by a gaseous detonation method. XRD analyses indicate that the main phase of the detonation product is carbon, a-Fe and y-Fe. TEM experiment indicates that the product is ultrafine spherical particles and the inner Fe core is coated by a carbon outer shell.The particles have equable size, regular sharp, and no agglomeration. The average diameter of Fe core is 4.5 nm;Raman spectrum analysis also confirms that the surface of the nanoparticles consists of graphite and amorphous carbon. The carbon-encapsulated iron particles were treated by heat treatment at low vacuum temperature of 673 K, and then we can find the size of iron core particles grows slightly;y-Fe phase turns to a-Fe phase and the saturation magnetization is more than doubled after heat treatment.