SmCo5纳米颗粒和纳米薄片的制备、结构和磁性能

采用表面活性剂增强高能球磨技术及颗粒清洗、分级筛选工艺,制备了具有较高矫顽力、颗粒尺寸分布狭窄的SmCo₅纳米颗粒与纳米薄片,利用XRD,SEM,TEM,激光粒径分析（LPSA）和振动样品磁强计（VSM）等手段分别对其相结构、微观形貌、颗粒尺寸分布及磁性能进行了表征.结果表明,平均颗粒尺寸分别为9.8和47.5 nm的SmCo₅纳米颗粒,其室温矫顽力分别为6.8×10⁴和7.3×10⁵A/m;SmCo₅纳米薄片的平均颗粒尺寸为1.4μm,平均厚度为75 nm,具有明显的c轴织构和较强的磁各向异性,其难磁化轴和易磁化轴上的室温矫顽力分别可达5.5×10⁵和1.6×10⁶A/m;SmCo₅纳米颗粒和纳米薄片的矫顽力表现出显著的颗粒尺寸依赖性.

PREPARATION,STRUCTURE AND MAGNETIC PROPERTIES OF SmCo5 NANOPARTICLES AND NANOFLAKES

Surfactant-assisted high energy ball milling technique is a new method of producing magnetic nanoparticles.In this study,permanent magnetic SmCo₅ nanoparticles and nanoflakes with high room-temperature coercivity values and narrow particle size distributions were produced by this technology and a subsequent size-selection process.The SmCo₅ nanoparticles with average particle sizes of 9.8 and 47.5 nm,exhibited room-temperature coercivity values of 6.8×10⁴ and 7.3×10⁵ A/m, respectively,while the SmCo₅ nanofiakes,with the mean particle size of about 1.4μm and average thickness of 75 nm,showed excellent permanent magnetic properties with an obvious c-axis crystal texture,a strong magnetic anisotropy and high coercivity values of 5.5×10⁵ and 1.6×10⁶ A/m in their easy-axis and hard-axis directions,respectively.The coercivity values of SmCo₅ nanoparticles and nanofiakes exhibited a significant particle size dependance effect.