کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5426147 | 1395878 | 2007 | 9 صفحه PDF | دانلود رایگان |
Crystal growth has been promoted in the fluid cell of an Atomic Force Microscope (AFM) by passing Ba-Sr-SO4 aqueous solutions over barite (0Â 0Â 1) cleavage surfaces. Steps advance in structural continuity with the original barite (0Â 0Â 1) surfaces and two-dimensional nucleation occurs preferentially on the newly-formed terraces. The terraces are, on average, 7.5% lower than pure barite terraces. Since the ionic radius of Sr2+ is smaller that the ionic radius of Ba2+, the reduction of terrace height is consistent with an extensive incorporation of Sr2+ into the barite structure. Therefore, it can be considered that the newly-formed terraces have compositions corresponding to terms of the BaxSr1âxSO4 solid solution. A non-linear dependence of step rate on [SrSO4] concentration in the solution (and therefore on supersaturation) has been found. The growth behaviour has been discussed by considering both the physicochemical properties of the BaxSr1âxSO4 solid solution-aqueous solution (SS-AS) system and a kinetic-based step growth model.
Journal: Surface Science - Volume 601, Issue 2, 15 January 2007, Pages 381-389