Chains of carbon atoms: A vision or a new nanomaterial?

Abstract

SummaryLinear strings of sp1-hybridized carbon atoms are considered as a possible phase of carbon since decades. Whereas the debate about the stability of the corresponding bulk phase carbyne continues until today, the existence of isolated chains of carbon atoms has meanwhile been corroborated experimentally. Since graphene, as the two-dimensional sp2-bonded allotrope of carbon, has become a vast field, the question about the importance of one-dimensional carbon became of renewed interest. The present article gives an overview of the work that has been carried out on chains of carbon atoms in the past one or two decades. The review concentrates on isolated chains of carbon atoms and summarizes the experimental observations to date. While the experimental information is still very limited, many calculations of the physical and chemical properties have been published in the past years. Some of the most important theoretical studies and their importance in the present experimental situation are reviewed.

Scaling Limits of Graphene Nanoelectrodes

“…At very large voltages of ~120-150 V, dielectric breakdown of the underlying SiO2 substrate is seen to occur. We attribute the absence of filamentation in wider gaps to instabilities of long carbon filaments 28,29 . …”

Carbon-atom wires: 1-D systems with tunable properties

“…Such an architecture is not only intriguing for theoretical predictions, but it has been recently realized and imaged by a TEMbased approach. 7,31,111 CAWs between graphene domains have been realized but, even with TEM images showing the atomic structure of the chain, no evidence for either cumulene or polyyne structures was given. 111 New insight into the structure of CAWs has been recently provided indicating a possible bond alternation in wires suspended between graphene edges.…”

“…7,8 In fact, in an extended linear sp-carbon system forming a CAW, the semiconductive/metallic behaviour results from the trade-off between Peierls distortion (which favours semiconductivity) and endgroup effects, which can stabilize metallic structures. Hence, sp-hybridized CAWs are intriguing systems with structure-, length-, and endgroup-dependent properties.…”

“…149 Recently, F. Banhart and co-workers reported the measurements of transport properties in single CAWs suspended between graphene edges. 7,150,151 The system was fabricated in a TEM starting from graphene and in situ characterized. In particular, by measuring the wires under strain they were able to observe a change in the current-voltage curves indicating a metal-to-semiconductor transition.…”

Electronic torsional sound in linear atomic chains: Chemical energy transport at 1000 km/s

“…Although the metallic behavior of cumulene was predicted theoretically 24,28 it is not confirmed experimentally 29,30 so the nature of electronic excitations remains unclear. Here we ignore electronic excitations assuming that there is the significant spectral gap (cf.…”