Clara Freytag

The resonant Raman response is due to electronic and vibrational excitations. Confined carbyne is a novel one dimensional heterostructure consisting of the linear carbon chain and a hosting carbon nanotube in the bulk limit. The resonant Raman fingerprint of confined carbyne comes concomitant with several new features which can neither be assigned to the hosting tube, nor to the linear carbon chain. This identifies the tube-chain system as a true hybrid structure in which the spectrum is usually driven by modifications in the electronic excitations via charge transfer. We show that the electronic structure results from those of the two isolated systems and the spectral modifications are solely due to the anharmonic interactions between the tube and the chain. Our work establishes confined carbyne as the ideal test system to probe anharmonicity in one dimension and its implications on the resonant Raman response.

Low-dimensional carbon allotropes belong to the most revolutionary materials of the most recent decades. Confined carbyne, a linear chain of sp¹-hybridized carbon encapsulated inside a small-diameter carbon nanotube host, is one extraordinary nanoengineering example. Inspired by these hybrid structures, we demonstrate the feasibility to synthesize nitrogen-doped confined carbyne by using azafullerenes (C₅₉N) encapsulated in nanotubes ("peapods") as precursors for the growth of confined carbyne. Resonance Raman spectroscopy as a site selective local probe has served to identify the changes in the spectra of nitrogen-doped versus pristine carbon peapods and confined carbyne. We are able to disentangle frequency changes due to charge transfer from changes due to the difference in mass for both the nanotube and the carbyne, where different effects dominate. This study demonstrates a suitable pathway to achieve controlled doping of carbyne chains via the use of specifically doped precursors.

Low-dimensional carbon allotropes belong to the most revolutionary materials of the last decades. The latest materialization of confined carbyne, a linear chain of sp1-hybridized carbon encapsulated inside a small-diameter carbon nanotube host, is one extraordinary nano-engineering example. Inspired by these hybrid structures, in this work, we demonstrate the feasibility to synthesize nitrogen-doped confined carbyne by using azafullerene (C59N) molecules encapsulated in nanotubes ("peapods") as precursors for the growth of confined carbyne. Resonance Raman spectroscopy as a site selective local probe has served to identify the changes in the spectra of nitrogen-doped versus pristine carbon peapods and confined carbyne. We are able to disentangle the frequency change due to charge transfer from the change due to the difference in mass for both the nanotube and the carbyne chain. We observe that the changes in the nanotube are dominated by the mass effect and the changes for confined carbyne are dominated by charge transfer. This study demonstrates a suitable pathway to achieve controlled doping of carbyne chains via using specifically doped precursors.

Confined carbyne, an sp ¹ ‐hybridized linear carbon chain inside a carbon nanotube, is a novel material with remarkable properties and potential applications. Among its currently successful synthesis methods, high temperature high vacuum annealing is prevalent. Further optimization could be achieved by tuning the synthesis pathway. Here, a systematic analysis of key synthesis parameters including precursor filling, annealing step sequences, and temperature conditions during high temperature vacuum processing is performed. A novel yield determination model that overcomes previous limitations related to the irregular resonance Raman behavior of carbyne is applied to evaluate bulk yield and realized growth potential. With this refined model, it is possible to make a quantitative assessment of bulk yield optimization potential in multi‐step annealing processes. These results provide crucial insights into the fundamental formation mechanisms of confined carbyne, advancing our understanding of this promising hybrid nanomaterial system. It is therefore possible to establish improved protocols for maximizing confined carbyne yields through precise control of synthesis conditions.

Anthropogenic activities threaten many wildlife populations by increasing mortality rates, making it crucial to identify the locations and causes of mortality to inform conservation actions. Technological advancements, such as GPS satellite tracking, enable precise recording of wildlife movements. High‐resolution data from such devices can facilitate rapid carcass recovery and provide insights into the mortality causes of tagged individuals. Obtaining required information to determine these causes is complex, and standardized approaches can overcome these limitations. In this study, we introduce the LIFE EUROKITE Assessment Protocol (LEAP), a framework for determining the timing, locations, and causes of mortality in GPS‐tagged birds. LEAP is a multifaceted approach that integrates: (1) GPS tracking data, (2) evidence from the mortality location (site investigation), and (3) necropsy results to derive the mortality cause and a corresponding certainty score. We supplement the detailed description of LEAP with case studies assessing its effectiveness. Using 329 deceased GPS‐tagged red kites (Milvus milvus) we compared conditions of the carcasses processed using LEAP with 145 opportunistically collected raptor carcasses. We also show that LEAP improves carcass condition and therefore allows for higher quality necropsy results. Additionally, we assessed how availability among sources of information (tracking, site investigation and necropsy) influences the quality of mortality assessments. Applying LEAP with all data sources provided the highest quality assessments in 64% of cases. Some 35% of cases were of high quality without necropsy, instead drawing evidence only from tracking data and site investigations. Predation related mortality was less prevalent (11%) when relying on necropsy compared to cases without necropsy (36%), while poisoning showed the opposite trend. Furthermore, we provide guidelines and empirical examples of mortality assessments. Our standardized LEAP approach ensures the best use of all available information regarding mortality events in GPS‐tagged birds and advances wildlife mortality research as a valuable tool for conservationists and wildlife managers.

The resonant Raman response is due to electronic and vibrational excitations. Interestingly, the resonant Raman fingerprint of confined carbyne is highly unconventional and comes concomitant to several new features which can neither be assigned to the hosting tube, nor to the linear carbon chain a.k.a carbyne. This identifies the tube-chain system as a true hybrid structure in which the spectrum is usually driven by strong modifications in the electronic excitations via charge transfer. Surprisingly, we show that the electronic structure results from those of the two isolated systems and the large spectral modifications are solely due to the strong anharmonic interactions between the tube and the chain. Our work establishes confined carbyne as the ideal test system to probe strong anharmonicity in one dimension and its huge implications on the resonant Raman response.