ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Assembling soft interfaces and breaking tough ones

Date: 04.11.2013
Time: 03:40 p.m.
Place: Materials Day 2013, Ruhr-Universität Bochum, Bochum, Germany

Alessandro De Vita, Department of Materials and Molecular Modelling, King's College London, London, United Kingdom

Supramolecular self-assembly is a very promising route to the fabrication of highly ordered metal-organic interfaces whose electronic properties could dominate the performance of novel, advanced organic electronics devices. Typically, fine-tuning the level alignment across the interface would be highly desirable, which generated interest in assembly strategies allowing control of the electric dipole associated with the first interface molecular layer.

This talk will mainly focus on how electrostatic interactions affect the assembly and level alignment properties of organic molecular layers deposited on metal substrates. I will review how the electrostatic potential can be measured/calculated close to adsorbed molecules [1], and describe how charging effects allow the fabrication of “unlikely” molecular structures [2] and generally drive the assembly behavior [3-4]. Crucially, linkage alkali atoms co-adsorbed with negatively chargeable molecules can yield the assembly of stable “organic salt” layers [5], with the desired highly tunable electric dipoles [6].

The conclusive part of the talk will address the different problem of simulating chemical effects during fracture propagation (both catastrophic [7] and stress-corrosive[8]) in brittle materials, using the “Learn On The Fly” hybrid QM/MM scheme, and the projected performance of the scheme when applied to interface-dominated problems involving metal phases. Examples of interest for the mining and aerospace industries include fracture of mineral ores during crushing and grinding, and plastic deformation of nickel-based superalloys in low-stress, high temperature conditions.

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