Substrate effects on the growth of MGCL2 thin films

The dependence of the overlayer growth on the underlying substrate is illustrated in this study of MgCl{sub 2} thin films on the following substrates: Pd(111), Pt(111), Pd(100) and Rh(111). On Pd(111) and Pt(111), the TPD of the deposited MgCl{sub 2} showed a significant substrate-adsorbate interaction as evidenced by a monolayer desorption feature. The interaction was further attested by the formation of two monolayers LEED patterns -- Pd(111)-(4x4)-MgCl{sub 2} and Pd(111)-({radical}13 x {radical}13)-R 13.9{degrees}-MgCl{sub 2}. Also, on Pd(111) and Pt(111), a multilayer coverage pattern was grown, MgCl{sub 2} (1 x 1). When Pd(100) was used as the substrate, the monolayer desorption feature disappeared from the TPD as well as the two monolayer patterns seen on Pd(111), but a MgCl{sub 2} (1 x 1) pattern with multiple rotated domains was created as the multilayer coverage. This difference resulted from the fact that the Pd(100) does not possess the correct angle for the (0001) face of the MgCl{sub 2}. To preserve this angle, the deposition of MgCl{sub 2} was performed on Rh(111) and the reconstructed face of Pt(100). Again, evidence of the strong substrate-adsorbate interaction was gone. The buckling of Pt(100)`s surface layer caused this result. For the Rh(111), the lattice match wasmore » not preserved with the angle.« less