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DD6.3.1

Electrochemical Deposition of Ba1-xSrxMoO4 Thin Films at Room Temperature D.J. Gao1, 2, D.Q. Xiao1*, J. Bi1, 2, P. Yu1, W. Zhang1, G. L. Yu1, and J.G. Zhu1 1, Department of materials science, Sichuan University Chengdu 610064, China 2, College of Chemistry and Life Science, Sichuan Normal University, Chengdu 610066, China ABSTRACT





A series of well crystallized Ba1-xSrxMoO4 (0 x 1) films were prepared on molybdenum substrates in electrolytes embodied Ba2+ and Sr2+ ions by electrochemical deposition at room temperature. The composition x is controlled through the starting concentrations of Ba2+ and Sr2+ ions. The measurements of XRD, SEM and XPS for these materials were carried out. The XRD analyses show that the films are good crystalline with single tetragonal structure of scheelite-type, and the a and c axes of the unit cell parameters of the films decrease with the increasing of Sr2+ concentration in the starting electrolytes; the XPS analyses reveal that the composition of the Ba1-xSrxMoO4 films is in agreement with stoichiometry, and the SEM photographs show that the films are condensed deposited.

INTRODUCTION The scheelite-type films of alkaline-earth tungstate and molybdate are important photo-electronic materials because the films have good properties of luminescence [1-2]; but the conventional techniques for preparing these thin films with good quality require high temperature treatment. Those high temperature treatments easily lead to the loss of adherence; furthermore, it is very difficult to obtain scheelite-structure single phase. On the other hand, the films of those molybdates and tungstates are necessary for the applications in various devices because of their better performance. Therefore it is very important to develop new mild ecological conscious processing methods for these films. Electrochemical method is one of the Soft Solution Processing (SSP)[3] methods, and also an environmental and ecological conscious method. The electrochemical method has several advantages over conventional films techniques [4-5]: (1) the thickness and morphology of the deposited films can be controlled by the electrochemical deposition parameters; (2) relatively uniform deposits can be obtained on complex shapes; (3) the deposition rate is higher than most of other methods; and (4) the cost is lower for deposition equipment. Better films can be obtained at low temperature by using this technique.

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Corresponding author: D. Q. Xiao, Department of Materials Science Sichuan University Chengdu 610064 China; Tel: +86-28-85415045, 85412415 Fax: +86-28-85415045; E-mail: [email protected].




DD6.3.2

Recently, CaWO4, SrWO4, Ba1-xSrxWO4 and BaMoO4 films et al are reported to be prepared at room temperature on metal substrate [6-9]. This work was devoted to the preparation of the crystalline Ba1-xSrxMoO4 (0 x 1) films directly from alkaline solutions at room temperature by using electrochemical deposition method.





EXPERIMENTAL PROCEDURES



Molybdenum metal substrates with purity more than 99.9% a