55 research outputs found
The low-field conductivity of zeolite-encapsulated molecular wires
The first measurements of an upper bound for the low-field conductivity of a molecular wire are
presented here. We were able to encapsulate polypyrrole with chain lengths more than 10 monomers
within the channels of different zeolites. Although the chains are fully oxidized by intrazeolite Fe3 +
ions, and should conduct (when included in a bulk polymer), they do not exhibit, in the zeolite,
significant ac conductivity up to 1 GHz. This suggests that other strategies than low field conductivity
are needed to inject charges and transmit information through isolated molecular wires
Recommended from our members
Life in the Atacama — Year 2: Geologic reconnaissance through long-range roving and implications on the search for life
The Life in the Atacama-2004 project, which included geological, morphological, and mineralogical mapping through combined satellite, field-based, and microscopic perspectives and long-range roving, led to the localization of potential habitats
Recommended from our members
Spectroscopic results from the Life in the Atacama (LITA) project 2004 field season
Analysis of spectroscopy datasets from rover field tests in the Atacama Desert (Chile), focusing on the composition of the surface and identification of potential habitats for life
A Picture of the Research Field of Doctoral Education from the Students’ Perspectives : Studies Using Questionnaires and Scales
Peer reviewe
Research productivity and academics’ conceptions of research
This paper asks the question: do people with different levels of research productivity
and identification as a researcher think of research differently? It discusses a
study that differentiated levels of research productivity among English and Australian
academics working in research-intensive environments in three broad discipline areas:
science, engineering and technology; social science and humanities; and medicine and
health sciences. The paper explores the different conceptions of research held by these
academics in terms of their levels of research productivity, their levels of research training,
whether they considered themselves an active researcher and a member of a research team,
and their disciplinary differences
STABILITY OF THE MAGNETIC POLARON
On étudie la stabilité du polaron magnétique dans un semiconducteur ferromagnétique à bande large. Utilisant la méthode des fonctions de Green on développe les équations de mouvement aux systèmes électroniques et magnétiques jusqu'à deuxième ordre en constante du couplage d'échange. On trouve que dans les chalcogénes de Eu le polaron est stable dans une région relativement large au voisinage de TC.The stability of the magnetic polaron is studied in a broad band ferromagnetic semiconductor. Using the Green's function techniques the equations of motion for the electronic and magnetic systems are developed up to second order in the exchange coupling constant. It is found that in Eu chalcogenides the polaron is stable in a relatively broad region around TC
ELECTRON SPIN RESONANCE STUDIES OF MAGNETIC DEFECTS IN FeCl3-DOPED POLYPARAPHENYLENE (p-C6H4) x
Nous avons étudié les spectres RPE du (C6H4)x dopé avec FeCl3. La concentration en spins de type Curie, la dépendance avec T de la largeur de raie et un shift du facteur g dus au dopage sont interprétés en terme de formation de polarons et bipolarons. Dans le matériau fortement dopé, l'espèce Fe3+ de haut spin donnant des largeurs de raie importantes a été identifiée.ESR spectra of FeCl3 -doped (C6H4)x have been studied. The concentration of Curie-law spins, T-dependence of the linewidth and a shift in the g-factor due to doping are accounted for by polaron and bipolaron formation in doped samples. In heavily doped material high Fe3+ spin densities with broad linewidths were found
- …