Co-SiO_2 颗粒膜中颗粒相互作用的温度和尺寸依赖关系(英文)  

TEMPERATURE AND SIZE DEPENDENT INTERPARTICLE INTERACTIONS IN Co-SiO_2 GRANULAR FILMS

作　　者：赵志军[1] 王兵[1] 王海千[1] 

机构地区：[1]中国科学技术大学结构分析中心,安徽合肥230026

出　　处：《低温物理学报》2002年第4期254-259,共6页Low Temperature Physical Letters

基　　金：国家自然科学基金 (Nos.5 9972 0 36,10 1740 73,1990 40 12 );国家重点基础研究专项经费 (G19990 75 30 5 );中科院量子结构中心基金资助~~

摘　　要：我们在真空离子束溅射设备中制备了Co SiO2 颗粒膜 .其结构和磁性分别利用透射电子显微术 (TEM)和铁磁共振 (FMR)来研究 .TEM分析表明Co纳米颗粒相互独立地分布在SiO2介质中 ,且尺寸分布非常窄 .室温转角FMR实验显示薄膜具有单轴各向异性 .变温FMR实验被用来研究在 10 0～ 30 0K温度范围内的颗粒间相互作用强度随温度变化的关系 (我们利用一理论模型计算了颗粒集合体中的铁磁部分所占比例和超顺磁部分所占比例 ) .我们发现颗粒间相互作用强度除了与温度有关之外 。Co-SiO-2 magnetic granular films were prepared with ion-sputtering method. Structures and magnetic properties of the films were studied by transmission electron microscopy (TEM) and ferromagnetic resonance (FMR) respectively. TEM analysis reveals that isolated Co nanoparticles disperse in the SiO-2 matrix with very narrow size distributions. Angular variational FMR experiments indicate uniaxial anisotropies in the films. The temperature dependence of FMR data is employed to determine the degree of interparticle interactions in a temperature range of 100～300K, ferromagnetic fraction and superparamagnetic fraction are calculated. We find that the degree of interparticle interactions depends not only on the temperature, but also on the size of the Co nanoparticles.

关 键 词：Co-SiO2颗粒膜 温度 尺寸 依赖关系 真空离子束溅射 薄膜 颗粒相互作用 

分 类 号：O484.43[理学—固体物理]