Size-dependent Surface States on Strained Cobalt Nanoislands on Cu(111)

TL;DR

This study investigates how the surface electronic states of strained cobalt nanoislands on Cu(111) depend on their size, revealing size-dependent energy shifts driven by mesoscopic relaxations.

Contribution

It demonstrates the size-dependent variation of surface states in cobalt nanoislands and links these shifts to mesoscopic relaxations through simulations and calculations.

Findings

Occupied states shift downward as island size decreases

Surface state positions vary significantly across islands

Size-dependent relaxations drive the observed energy shifts

Abstract

Low-temperature scanning tunneling spectroscopy over Co nanoislands on Cu(111) showed that the surface states of the islands vary with their size. Occupied states exhibit a sizeable downward energy shift as the island size decreases. The position of the occupied states also significantly changes across the islands. Atomic-scale simulations and ab inito calculations demonstrate that the driving force for the observed shift is related to size-dependent mesoscopic relaxations in the nanoislands.