BN包覆Co纳米胶囊的制备和性能  

Preparation and properties of BN coated Co/CoB nanocapsules

作　　者：史桂梅[1] 董阳[1] 黄炎[1] 张金虎[1] 

机构地区：[1]沈阳工业大学

出　　处：《材料研究学报》2008年第4期379-383,共5页Chinese Journal of Materials Research

基　　金：国家自然科学基金50571070;辽宁省自然科学基金20062038资助项目~~

摘　　要：用直流电弧等离子法蒸发Co-B非晶合金,以Co-B非晶合金靶材,制备了BN包裹Co和少量CoB合金的纳米颗粒,用高分辨电镜、X-Ray衍射及选区电子衍射和光致发光光谱及红外光谱对其进行了表征.结果表明,所制备的纳米颗粒是一种具有核壳结构的纳米胶囊,尺寸为10-100 nm,核由Co和少量CoB合金组成,壳是厚度为3-5 nm的BN;Co/CoB作为催化剂在蒸发时促使B与N反应,生成BN包覆在其表面形成纳米胶囊.壳核结构能防止纳米Co颗粒的氧化和团聚.这种纳米胶囊的饱和磁化强度为63.16 Am^2/kg,矫顽力为23.16 kA/m.其矫顽力比相应的块体材料提高的主要原因,是颗粒尺寸变小和多畴粒子畴壁的钉扎作用.BN coated Co and few bulk Co-B amorphous alloy. HRTEM shows CoB alloy nanocapsules were prepared by arc-discharging a the as-prepared nanoparticles form in a core-shell structure, with the size of nanoparticles in range of 30-100nm and the thickness of the shell 3-5nm. X-Ray and Selected area electron diffraction （SAED） patterns show core consist of Co and few CoB alloy, while the shell consist of BN measured by FTIR spectra and photoluminescence spectra （PL）. That BN coated Co/CoB nanoparticles form in a core-shell structure are ascribed to Co/CoB as catalysts accelerating reaction between B with N ionize in the arc-discharge course.The core-shell structure can prevent Co/CoB nanoparticles from oxidation and agglomeration. A saturation magnetization of Ms=03.16 Am2/kg and a coercive force of Hc=23.16 kA/m are achieved for as-prepared nanocapsules by VSM. The coercive force increasing for as-prepared particles can be mainly ascribed to size of particles diminished and the domain-wall depinned in the multidomain particles.

关 键 词：无机非金属材料 电弧法 纳米胶囊 磁性质 Co(BN) 壳核结构 光谱 

分 类 号：O482[理学—固体物理]