钼酸钡薄膜的原电池及电解型电化学制备技术比较研究

Comparative investigations on BaMoO_4 thin films prepared by cell and electrolysis electrochemical techniques

分别采用恒电流电化学技术和原电池电化学技术在钼片上制备出了具有单一白钨矿结构的钼酸钡薄膜,并对薄膜的相结构、表面形貌、元素价态及钼材料的利用率进行了深入的比较研究。研究发现,两条电化学路线制备的钼酸钡薄膜都是结晶良好的,具有单一的白钨矿结构;晶粒呈四方锥形;薄膜中的钡、钼和氧元素分别表现为+2、+6和-2价。但采用原电池路线时,钼酸钡薄膜更加致密,晶粒更加均匀,表面较为平坦;而且,电化学溶解的钼能够更好地凝聚成钼酸钡附着在阳极表面;与之相对应,在恒电流条件下,有相当大一部分钼酸根离子扩散进入了电解液中。

Scheelite-structured barium molybdate thin films have been prepared on molybdenum substrates by using constant current technique and cell electrochemical technique respectively. Their structures, surface morphologies, element valences and the utilization ratio of molybdenum have been investigated in detail. Researches reveal that barium molybdate thin films prepared by both electrochemical routines are well crystallized in scheelite strueture; and the crystals grow in tetragonal tapers; and the valences of barium, molybdenum and oxygen element in the films are ＋2, ＋ 6 and ＋2 respectively. Under cell conditions, the crystals are more homogeneous and the films become denser and smoother. Moreover, it is more efficient for those dissolved molybdenum to nucleate and form barium molybdate thin films by cell route.