Initial stages of nickel oxide growth on Ag(001) by pulsed laser deposition

TL;DR

This study investigates the initial growth stages of nickel oxide films on Ag(001) using pulsed laser deposition, revealing defect formation and growth mechanisms through in-situ microscopy and spectroscopy.

Contribution

It provides new insights into defect types and nucleation processes during nickel oxide film growth on silver substrates.

Findings

Quasi-two-dimensional growth observed

Identification of metallic Ni clusters and oxygen atoms as defects

Defects influence nucleation and film growth

Abstract

Submonolayers of nickel oxide films were grown on an Ag(001) by pulsed laser deposition, and characterized in-situ by both scanning tunneling microscopy and X-ray photoelectron spectroscopy. We observed quasi-two-dimensional growth of the film, and clearly identified several kinds of defects, such as embedded metallic Ni clusters and, notably, oxygen atoms, even while looking deeply into the substrate. These originated from Ni and O hyperthermal projectiles as well as from NiO clusters that were formed during laser ablation of a NiO target. Those defects played a role of nucleation sites in extending the nucleation stage of thin film growth.