Electric Conductance of Rh Atomic Contacts under Electrochemical Potential Control

TL;DR

This study investigates how electrochemical potential influences the electrical conductance of Rh atomic contacts, revealing potential-dependent conductance features and comparing them with other metals to understand hydrogen-metal interactions.

Contribution

It provides new insights into the electrochemical control of atomic-scale conductance in Rh contacts and compares these behaviors across different metals.

Findings

Conductance histogram varies with electrochemical potential.

Feature at 2.3 G0 observed at -0.1 V, matching vacuum conditions.

Features at 0.3 and 1.0 G0 observed at -0.25 V.

Abstract

The electric conductance of Rh atomic contacts was investigated under the electrochemical potential control. The conductance histogram of Rh atomic contacts varied with the electrochemical potential. When the electrochemical potential of the contact was kept at $\Phi_{0}$= 0.1 V vs. Ag/AgCl (Rh potential), the conductance histogram did not show any features. At $\Phi_{0}$= -0.1 V (under potential deposited hydrogen potential), the conductance histogram showed a feature around 2.3 $G_{0}$ ($G_{0}$ =2$e^{2}/h$), which agreed with the conductance value of a clean Rh atomic contact, which was observed in ultrahigh vacuum at low temperature. At $\Phi_{0}$= -0.25 V (over potential deposited hydrogen potential), the conductance histogram showed features around 0.3 and 1.0 $G_{0}$. The conductance behavior of the Rh atomic contact was discussed by comparing previously reported results of other metals, Au, Ag, Cu, Pt, Pd, Ni, Co, and Fe. The conductance behavior of the metal atomic contacts related with the strength of the interaction between hydrogen and metal surface.