CoPt_3纳米线阵列的制备及特性研究  

Study on Preparation and Magnetic Properties of CoPt_3 Nanowire Arrays

作　　者：牛宇然[1] 陈子瑜[1] 黄沛霖[1] 武哲[1] 

机构地区：[1]北京航空航天大学物理系,北京100083

出　　处：《信息记录材料》2005年第2期51-54,共4页Information Recording Materials

基　　金：教育部<高等学校骨干教师资助计划>[(2000)65号]资助的课题

摘　　要：在具有纳米级孔洞的多孔氧化铝模板上,用电化学方法成功地制备了CoPt3纳米线有序阵列复合膜。分别用透射电子显微镜(TEM)、选区电子衍射(SAED)、X射线衍射(XRD)、振动样品磁强计(VSM)和SQUID对样品进行了测试与表征。形貌观察和物相分析表明,模板中的CoPt3纳米线构成的阵列,排列均匀有序,长约1.5微米,直径35纳米;而纳米线中的CoPt3为L12无序结构。磁性研究表明,纳米线的无序晶体结构决定了纳米线阵列弱的磁晶各向异性;同时纳米线中部分小晶粒在400K左右表现出顺磁性,导致纳米线阵列居里温度的下降。比较低温和室温下的磁滞回线,低温下有大的矫顽力,从另一方面证明纳米线中的小晶粒确实存在相转变。Arrays of CoPt3 nanowires have been prepared by co-depositing Pt and Co into porous anodic alumina template. The samples were measured and characterized by transmission electron microscope (TEM) , selected area electronic diffraction (SAED) , x-ray diffraction(XRD), vibrating sample magnetometer (VSM) and SQUID, respectively. TEM results show that the nanowires are regular and uniform, about 1. 5μm in length and 35nm in diameter. Structural determination by XRD indicates that Ll2 CoPt3 phase appears with random order fcc structure in each nanowire. Magnetic measurement by VSM and SQUID shows that the arrays of nanowires exhibit weak magnetic anisotropy which is dependent on the degree of crystallite random / order in each nanowire. Magnetic hysteresis loops measured at temperatures from 1.9 K to 800 K demonstrate that the nanowire arrays exist super-paramagnetic phase which result in the decrease of curie temperature.

关 键 词：纳米线阵列 特性研究 制备 多孔氧化铝模板 透射电子显微镜 振动样品磁强计 选区电子衍射 磁晶各向异性 电化学方法 X射线衍射 SQUID 有序阵列 形貌观察 无序结构 磁性研究 晶体结构 居里温度 磁滞回线 小晶粒 纳米级 复合膜 

分 类 号：TM936.1[电气工程—电力电子与电力传动] TB383[一般工业技术—材料科学与工程]