电化学法制备BaMoO_4和SrMoO_4薄膜的生长特性比较研究(I):共性分析

采用恒电流电化学技术直接在金属钼片上制备了具有白钨矿结构的钼酸盐(BaMoO4、SrMoO4)薄膜,对制备时间分别为10s直到50min的BaMoO4薄膜和制备时间分别为1min直到100min的SrMoO4薄膜的生长情况进行了SEM测试,并对相应结果进行了对比分析。研究表明:用电化学法制备BaMoO4和SrMoO4晶态薄膜,其生长特性既具有共性,也具有鲜明的个性。其共性特征是:1)成膜机制相同;2)薄膜生长初期就有比较完整的晶核生成;3)晶核和晶粒优先选择在金属基体缺陷(折叠、划痕、缺陷、凹凸不平等)处堆砌和生长;4)基体上晶粒的数量随着制备时间的增加而增加,晶粒的尺寸也随着时间的延长而长大,晶粒逐渐从稀疏分布到布满整个基体;5)在具有白钨矿结构的钼酸盐晶态薄膜的生长过程中,晶体的{111}面总是显露的。其鲜明的个性特征将在另文中讨论。该研究结果对功能晶态薄膜的生长(特别是利用电化学技术制备功能晶态薄膜的生长)和了解及预测白钨矿结构的晶态薄膜的生长习性,均具有重要意义。

Comparative Studies on the Growth of BaMoO_4 and SrMoO_4 Thin Film by Using Electrochemical Technique:(I) Common Characteristics

Barium molybdate(BaMoO_4) and strontium molybdate(SrMoO_4) crystalline films with scheelite-structure were prepared directly on metal molybdenum substrates by using constant current electrochemical technique.The SEM images of BaMoO_4 films deposited from 10 sec until 50 min and SrMoO_4 films deposited from 1 min until 100 min were carried out respectively,and the results were compared and analyzed.It is found that the growth of BaMoO_4 and SrMoO_4 crystalline thin film by using electrochemical method possesses the common characteristics and also the individuality.The common characteristics are: 1) The mechanism of the crystalline growth of the film is the same;2) The shape of the crystalline nucleuses is integrated at the beginning of the formation of the nucleuses;3) The places where these crystalline nucleus and granules pile up and grow are those of the defects such as the fold,nick,disfigurement,and cave and convex inequality at the substrate;4) The quantity and the size of the crystalline granules increase with the preparation time,the crystalline granules are dispersed gradually from sparseness to all over of the substrate;and 5) The {111} faces of SrMoO_4 crystals always appear during the growth.The individual characteristics of the film growth will be discussed in another paper.It is sure that the results are of great significance for the research of the growth of crystals and crystalline films,especially for the research of the growth of crystals and crystalline films by using electrochemical method.