I deposited the thin films of Pt on MgO with orientations 100,110,111 . By doing AFM I observe Granular structurs on MgO 100, then by keeping the deposition parameters same, I observe Island strucutres on MgO 110 , Then I observe nano flakes type structures on the MgO 111. by changing the substrate orientation and keeping the deposition parameters same i observe different a very different behavior by all three substrate orientation. What could be the possible reasons behind this output ??
Could you upload few examples of pictures?
Did you scan the MgO surfaces with all orientation before coating? Probably, there is just an artifact of the substrate surface.
Good luck!
Prof. Denis I am going to scan the MgO substrate for the reference . I will upload the images soon as possible.
Regards
Hassan
Different surface planes have different chemical potentials, and the Pt atoms will nucleate where the potentials are lowest. The chemical potential itself depends on orientation (i.e. atomic areal density), possible surface reconstruction and whether there are any steps on the surfaces, as mono-atomic surface steps are preferred nucleation sites. There is a whole area of surface physics on this. MgO surfaces, furthermore, are prone to hydroxyl damage, i.e. when water is absorbed, this etches the surface. So you are dealing with a very delicate material!
Really appreciate your answer dear Thomas Walter..it's so much useful for me.. thanks alot again of you precious time.
Regards
Hassan
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