Growth of all-carbon horizontally aligned single-walled carbon nanotubes nucleated from fullerene-based structures

All-carbon single-walled carbon nanotubes (SWCNTs) were successfully synthesized, nucleated using a fullerene derivative. A systematic investigation into the initial preparation of C60 fullerenes as growth nucleators for the SWCNTs was conducted. Enhancement in the yield of the produced SWCNT has been achieved with exploring different dispersing media for the fullerenes, the period, and environment of the initial thermal treatment of the fullerenes in addition to the use of different fullerene-based structures. The systematic studies significantly advance our understanding of the growth of the all-carbon catalyst-free single-walled carbon nanotubes. Field-effect transistors were fabricated using the catalyst-free SWCNT and then electrically characterized, showing current capacity as high as the well-studied catalyst-assisted nanotubes

Gain of a 500-fold sensitivity on an intravital MR Contrast Agent based on an endohedral Gadolinium-Cluster-Fullerene-Conjugate: A new chance in cancer diagnostics

Among the applications of fullerene technology in health sciences the expanding field of magnetic resonance imaging (MRI) of molecular processes is most challenging. Here we present the synthesis and application of a GdxSc3-xN@C80-BioShuttle-conjugate referred to as Gd-cluster@-BioShuttle, which features high proton relaxation and, in comparison to the commonly used contrast agents, high signal enhancement at very low Gd concentrations. This modularly designed contrast agent represents a new tool for improved monitoring and evaluation of interventions at the gene transcription level. Also, a widespread monitoring to track individual cells is possible, as well as sensing of microenvironments. Furthermore, BioShuttle can also deliver constructs for transfection or active pharmaceutical ingredients, and scaffolding for incorporation with the host's body. Using the Gd-cluster@-BioShuttle as MRI contrast agent allows an improved evaluation of radio- or chemotherapy treated tissues

Tunneling, Remanence, and Frustration in Dysprosium based Endohedral Single Molecule Magnets

A single molecule magnet (SMM) can maintain its magnetization direction over a long period of time [1,2]. It consists in a low number of atoms that facilitates the understanding and control of the ground state, which is essential in future applications such as high-density information storage or quantum computers [3,4]. Endohedral fullerenes realize robust, nanometer sized, and chemically protected magnetic clusters that are not found as free species in nature. Here we demonstrate how adding one, two, or three dysprosium atoms to the carbon cage results in three distinct magnetic ground states. The significantly different hysteresis curves demonstrate the decisive influence of the number of magnetic moments and their interactions. At zero field the comparison relates tunneling of the magnetization, with remanence, and frustration. The ground state of the tridysprosium species turns out to be one of the simplest realizations of a frustrated, ferromagnetically coupled magnetic system.Comment: 14 pages (latex file) + 3 seperate figures (jpeg

X-ray induced demagnetization of single-molecule magnets

Low-temperature x-ray magnetic circular dichroism measurements on the endohedral single-molecule magnet DySc2N@C-80 at the Dy M-4,M-5 edges reveal a shrinking of the opening of the observed hysteresis with increasing x-ray flux. Time-dependent measurements show that the exposure of the molecules to x-rays resonant with the Dy M-5 edge accelerates the relaxation of magnetization more than off-resonant x-rays. The results cannot be explained by a homogeneous temperature rise due to x-ray absorption. Moreover, the observed large demagnetization cross sections indicate that the resonant absorption of one x-ray photon induces the demagnetization of many molecules. (c) 2014 AIP Publishing LLC