Peculiar atomic bond nature in platinum monatomic chains

TL;DR

This study reveals unusual bond characteristics in platinum monatomic chains, showing higher stiffness than bulk and significant elastic stretching, explained by a new 'string tension' concept, advancing understanding of atomic bonds in 1D materials.

Contribution

The paper introduces a novel in-situ TEM method to measure bond stiffness in platinum chains, revealing their unique elastic and mechanical properties compared to bulk material.

Findings

Bond stiffness in chains exceeds bulk values.

Chains can elastically stretch by 24%.

Proposes 'string tension' as a new bond concept.

Abstract

Metal atomic chains have been reported to change their electronic or magnetic properties by slight mechanical stimulus. However, the mechanical response has been veiled because of lack of information on the bond nature. Here, we clarify the bond nature in platinum (Pt) monatomic chains by our developed in-situ transmission electron microscope method. The stiffness is measured with sub N/m precision by quartz length-extension resonator. The bond stiffnesses at the middle of the chain and at the connecting to the base are estimated to be 25 and 23 N/m, respectively, which are higher than the bulk counterpart. Interestingly, the bond length of 0.25 nm is found to be elastically stretched to 0.31 nm, corresponding to 24% in strain. Such peculiar bond nature could be explained by a novel concept of "string tension". This study is a milestone that will significantly change the way we think about atomic bonds in one-dimensional substance.