STM and ab initio study of holmium nanowires on a Ge(111) Surface

TL;DR

This study combines STM experiments and ab initio calculations to investigate holmium nanowires on Ge(111), revealing their growth, structure, and metallic properties without surface patterning.

Contribution

It presents a new structural model for Ho nanorods on Ge(111) and demonstrates their metallic nature through combined experimental and theoretical analysis.

Findings

Nanorods form without surface patterning or defects.

High coverage leads to a 5x1 periodic structure.

Nanorods exhibit metallic electronic character.

Abstract

A nanorod structure has been observed on the Ho/Ge(111) surface using scanning tunneling microscopy (STM). The rods do not require patterning of the surface or defects such as step edges in order to grow as is the case for nanorods on Si(111). At low holmium coverage the nanorods exist as isolated nanostructures while at high coverage they form a periodic 5x1 structure. We propose a structural model for the 5x1 unit cell and show using an ab initio calculation that the STM profile of our model structure compares favorably to that obtained experimentally for both filled and empty states sampling. The calculated local density of states shows that the nanorod is metallic in character.