Extraordinary mechanical performance in charged carbyne

Abstract

Carbyne, the linear chain of carbon, promises the strongest and toughest material but possesses a Peierls instability (alternating single-bonds and triple-bonds) that reduces its strength and toughness. Herein, we computationally found that the gravimetric strength, strain-to-failure, and gravimetric toughness can be improved from 74 GPa⋅g−1⋅cm3, 18%, and 9.4 kJ⋅g−1 for pristine carbyne to the highest values of 106 GPa⋅g−1⋅cm3, 26%, and 19.0 kJ⋅g−1 for carbyne upon hole injection of +0.07 e/atom, indicating the charged carbyne with record-breaking mechanical performance. Based on the analyses of the atomic and electronic structures, the underlying mechanism behind the record-breaking mechanical performance was revealed as the suppressed and even eliminated bond alternation of carbyne upon charge injection.