【作者】 李加新；

【导师】 赖恒； 黄志高；

【作者基本信息】 福建师范大学 ， 凝聚态物理， 2008， 硕士

【摘要】 稀土（RE）-铁族金属（IG）合金膜具有优异的磁、电、光等性质,多年来已广泛应用于电子、信息、能源等各个领域,对其研究开发备受关注。此外,采用电沉积方法制备此类合金膜具有成本低、效率高、组成易控制等优点。因此,本文采用电沉积方法在低温尿素熔盐中制备了稀土（RE=La,Sm,Gd）-铁族金属（IG=Fe,Co,Ni）合金膜,研究其电化学行为和沉积机理,并对合金膜进行晶化热处理,着重研究其热处理前后的晶相结构和磁特性机理及其相互影响关系等。主要工作如下:1、简要介绍了RE-IG合金膜的发展和应用价值,电沉积方法制备RE-IG合金膜的现状,磁性理论的基本概念和分类,及实现本工作的制备和测试条件。2、利用循环伏安法,研究了RE³⁺和IG²⁺在尿素-乙酰胺-NaBr-KBr熔体中的电化学行为,并计算获得IG²⁺电还原的扩散系数D₀和电荷传递系数α;研究了RE³⁺在熔体中被IG²⁺诱导实现共沉积的机理,并利用元素的电负性原理进行解释;研究了沉积条件对合金膜的成分和形貌的调节作用机制。3、首次归纳并得出在低温尿素熔体中所制备的系列非晶RE-IG合金膜的磁特性递变规律,且对非晶膜的磁特性机制进行解释;选择优化条件对非晶膜进行晶化处理,研究了退火后RE-IG合金膜的晶相和磁特性变化,及晶化后的磁性机制和晶相结构二者之间依赖关系。更多还原

【Abstract】 Rare earth （RE） - iron group metal （IG） alloy films have excellent magnetic, optical and electric properties, they have been investigated for many years for applications as electron, information technology, energy, and so on. Moreover, electrodeposition is an alternative method for preparing these alloy films. It has the advantage of being simple and cost-effectivenes, utilizing easily maintained equipment. Deposits can also be tailored through changing solution composition and deposition conditions. In this thesis, consequently, we have been prepared Rare earth （RE=La,Sm,Gd） - iron group metal （IG=Fe,Co,Ni） alloy films in low temperature urea-acetamide-NaBr-KBr-RECl₃-IGCl₂ baths by potentiostatic electrolysis. The electrochemical behavior and co-deposition mechanism were investigated. The phase structure and magnetic properties before and after heat-treatment were studied in detail. The main contents of this paper are arranged as follows:1. The development and application of RE-IG alloy films, the preparation method for electrodepositied RE-IG alloy films, the essential conception and sort of magnetic theory and the equipments for electrodeposition and test were introduced in brief, respectively.2. Cyclic voltammetry was used to investigate the electrochemical behavior of RE³⁺ and IG²⁺ in baths on a Pt electrode. The transfer coefficientαand the diffusion coefficient D₀ for IG²⁺ were measured, respectively. The co-deposition mechanism was explained well with the electronegativity theory. Finally, the dependence of composition and morphology of alloy films on electrodepositon conditions was investigated.3. The change trend of magnetic properties for amorphous RE-IG alloy films in urea molten salt was concluded firstly. The phase structure and magnetic properties after the best heat-treatment were studied.更多还原