15:30-16:00

Towards a tunable superconductivity transition in small molecule organic compounds by combined scanning probe microscopies

Organic superconductors are presented as cost-effective and large-area scalable superconductor materials. This kind of superconductors has recently gained greater appeal than their ceramic and metallic counterparts due to their fine-tailoring of electrical and structural properties, and because they offer a simple system to advance the fundamental understanding of superconductivity.

The recent opportunities provided by the simultaneous combination of STM and AFM to manipulate atoms and molecules and to simultaneously characterize their electronic structural and charge states opens new ways to explore classical concepts still not yet well understood at the nanoscale. To that effect, local manipulation of molecules or atoms may enable new methods to discriminate which parameters govern the superconductivity transition and creates new opportunities to control critical temperature in organic superconductors in an attempt to reach higher critical temperatures.

In this talk, I will describe an approach to characterize and manipulate electronic, chemical and structural properties at molecular and atomic scale of small molecule organic superconductors..

Speaker

Dr. César Moreno Sierra, ICYS-Sengen Researcher, NIMS

Chair

Dr. Noboru Miura, Managing Director, ICYS, NIMS

16:00-16:30

Solution assembly of pi-containing small-molecule hydrophobic amphiphiles

The work is based on a new concept in solution assembly: the non-polar solvent-driven micellization of a fully hydrophobic, small, functional molecule. Conventional “hydrophobic-hydrophilic” surfactants and polymers are known to form a variety of assembly states in solution. The hydrophobic and hydrophilic parts differ greatly, with very different intermolecular interactions, which help drive assembly. The new approach differs in that fully hydrophobic molecules consisting of a fullerene cage functionalized with just alkyl chains are used. Surprisingly, these derivatives are able to micellize in solvents favoring the alkyl part, with the solvent quality strongly dictating the aggregation size and extent. These micellar systems have been probed mainly using a combination of small-angle x-rays and neutron scattering (SAXS, SANS), and UV-visible absorbance spectroscopy. In this presentation, after introducing myself to the ICYS members, I will focus on our past efforts to control the micellization and finally present some recent results in which more extended solution-state structures have been pinpointed, which could find use in e.g. optoelectronic applications.

Speaker

Dr. Martin Hollamby, ICYS-Sengen Researcher, NIMS

Chair

Dr. Noboru Miura, Managing Director, ICYS, NIMS

16:30-17:00

Self-assembled monolayer (SAM): The puzzle

The SAMs of the dithiols molecules remains one of the enigmas in respect of configuration, because of the double active thiols function. I will present the behavior of this SAMs in different environments, and also the strategy used to obtain well-ordered SAMs. The study of the effect of X-ray and low-energy (50 eV) electron irradiation on both hexanethiolate (C6) and dodecanethiolate (C12) films shows that, in the case of C12/Au, the dominant processes were decomposition of the alkyl chains and capture of the released alkylsulfide moieties in the aliphatic matrix, desorption of the complete molecular species emerging after the cleavage of the thiolate-gold bond prevailed in the case of C6/Au. A tentative explanation for this behavior will be proposed in this talk. Finally, I will demonstrate, using the Core Hole Clock technology, how the efficiency of tunneling in molecular wires (MWs) can be significantly affected　by controlling the specific orbitals into which charge carriers are injected.

Speaker

Dr. Hicham Hamoudi, ICYS-MANA Researcher, NIMS

Chair

Dr. Noboru Miura, Managing Director, ICYS, NIMS