摘要
采用恒电流电化学技术直接在金属片M（钼或钨）上制备了具有白钨矿结构的不同体系（钼酸盐、钨酸盐）、不同时间（从薄膜开始生长到生长结束）的AMO4晶态薄膜，利用SEM技术、结合其它相关测试手段，对这些薄膜进行测试，对相应结果进行了对比分析。研究表明：在利用电化学法制备AMO4薄膜的过程中，薄膜的生长具有以下几个特性：（1）在电化学制备技术中，由电流密度分布不均匀使得基片缺陷处的电流密度大于其它位置的电流密度，使得这些位置的成核速率较大，因而晶核和晶粒优先选择在金属基体缺陷处堆砌和生长；（2）在薄膜的制备过程中，金属M发生电化学反应形成MO4^2-，一定量的MO4^2-沉积在基体表面并构成具有白钨矿结构的骨架，与A^2＋结合形成AMO4晶核和晶粒；（3）薄膜生长初期就有比较完整的晶核生成；（4）随着反应时间的延长，一方面新的晶核不断形成，基体上晶粒的密度不断增加；另一方面晶核和晶粒不断长大；经过这样的过程，最终晶粒布满整个基体形成致密的薄膜。
The AMO4 films with scheelite-structure which were the molybdate and tungstate films of the different system were prepared directly on metal M （molybdenum or tungsten） substrates in different time from the early stage to the terminal stage of film growth by using constant current electrochemical technique. These AMO4 films were tested through SEM and other correlative testing methods, and the results were compared and analyzed. It found that the growth processes of AMO4 films by using electrochemical technique have several characteristics as follow： （1） The current density at the defects of substrates is higher than other places due to its non-uniform distributing in the preparation of electrochemical technique, the nucleation velocity is larger, so these crystalline nucleus and granules choose the defects at the substrate to pile up and grow; （2） During the preparation of films, the metal substrates （M） form MO4^2- through electrochemical reaction, a quantity of MO4^2- deposit on the substrate and form the scheelite framework, then the A^2＋ ions fill in the framework resulting in the AMO4 crystalline nucleus and crystalline granules; （3） The shape of the crystalline nucleuses is integrated at the beginning of the formation of the nucleuses; （4） Along with the increase of the preparation time, on the one hand, the new crystalline nucleus shape continually result in the crystalline granules density increases continually on the substrate; on the other hand, the crystalline nucleus and granules grow up continually; through this process, the crystalline granules bestrew the whole substrate to form the compact thin films finally.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2007年第A10期4067-4069,共3页
Journal of Functional Materials
基金
国家自然科学基金重大国际合作资助项目（50410179）
国家自然科学基金面上资助项目（50372042）
霍英东青年教师基金资助项目（94008）
关键词
电化学技术
白钨矿结构
钼酸盐
钨酸盐
晶态薄膜
electrochemical technique
scheelite-structure
molybdate
tungstate
crystalline films
