采用恒电流电化学技术直接在金属钼片上刺备了具有白钨矿结构的钼酸盐(BaMoO4)薄膜,着重在实验上研究了电化学技术制备BaMoO4薄膜的初期生长特性。对制备时间分别为10、30s、1、3、5、8直到50min(制备完毕)的BaMoO4薄膜进行了SEM测试,并对相应的测试结果进行了对比和分析。研究表明,用电化学法制备的BaMoO4晶态薄膜在生长初期具有如下特点:薄膜生长之初就有比较完整的晶核生成;晶核和晶粒优先选择在基体缺陷(折叠、划痕、缺陷、凹凸不平等)处堆砌和生长;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增加而长大,晶粒逐渐从稀疏分布到布满整个基体;晶体的{111}面总是显露的;在薄膜生长的初始阶段,晶粒基本上以其c轴垂直于薄膜基体表面进行生长;随着薄膜制备时间的延长,晶粒的生长方向按其c轴在薄膜的表面内的方向进行生长。上述研究结果对了解和控制利用电化学法制备晶态薄膜的生长,具有重要意义。
Barium molybdate (BaMoO4) films with scheelite-structure were prepared directly on metal molybdenum suhstrates by using constant current electrochemical technique with emphasizing on the growth characteristics of the films at the early stages. The SEM images of the films deposited for 10, 30s, 1, 3, 5, 8min until 50min were carried out respectively, and the results were compared and analyzed. It is found that the growth of BaMoO4 crystalline thin film by using electrochemical method at their early stages possesses special characteristics as follows: there are integrated crystalline nucleuses at the beginning of growth; the places where these crystalline nucleus and granules pile up and grow prior are those of the defects such as the fold, nick, disfigurement, and cave and convex inequality etc at the substrate; the quantity and the size of the crystalline granules increase with the preparation time; the crystalline granules are dispersed gradually to all over of the substrate; the {111} faces of BaMoO4 crystal always appear during the growth; the crystalline granule grows in the direction that its c axis is perpendicular to the surface of the substrate; and along with the extension of deposition time, the growth direction of the crystalline granule trends to its c axis being in the surface of the film. It is sure that the results are of great significance for crystal growth and for controlling the growth of crystalline films by using electrochemical method.