Tunneling voltage dependent heights of faulted and unfaulted Ir islands on Ir„111..
نویسندگان
چکیده
Analysis of homoepitaxial growth on Ir~111! by scanning tunneling microscopy ~STM! reveals that two different phases nucleate. We find islands in the regular face-centered cubic ~fcc! stacking as well as in the hexagonal close-packed ~hcp! stacking. Performing STM measurements on fcc and hcp areas shows an apparent, voltage dependent height difference of up to 6% of the regular layer distance. By applying first-principles calculations, the voltage dependent height difference can be attributed to the difference in the electronic structures of the two phases. The atoms in hcp stacking appear lower for a wide range of tunneling voltages, opposite to the actual relaxation.
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