IMX Seminar Series - Atomistic Modeling

Metallic glasses are a class of amorphous materials that are strongly out of equilibrium. Their remarkable thermo-mechanical properties, including a very robust elastic regime, make them industrially relevant for applications in extreme environments. Despite the lack of long range order, structural heterogeneities do exist, which are closely related to spatial variations in relaxation time-scales and therefore properties of the disordered solid. Indeed, relaxation time-scales are intimately connected to the degree of relaxation of the glassy structure which in turn can be controlled either through a thermal and/or mechanical processing protocol. In this talk, I will present atomistic simulations spanning several microseconds of physical time, timescales which begin to probe dissipation, transport and ultimately the thermally activated micro-plasticity of a model glass. The atomic-scale processes facilitating these phenomena, and more generally glass structural evolution, will be discussed in terms of the seminal works of Frank, Kasper, Turnbull and Nelson, demonstrating that despite the strong disorder, amorphous structure is strongly constrained, and it such constraints that play a fundamental role in determining the microscopic properties of a glass.
Bio: In 1995, PD obtained a PhD in Quantum Electrodynamics from the physics Department at Monash university, Melbourne, Australia. After a postdoc studying the electronic properties of porous silicon, he moved to Trondheim-Norway for a postdoc working on Series 6000 Aluminium alloys. In 2000, he became a staff-scientist at the Paul Scherrer Institute, performing atomistic simulations focused on nano-crystalline metals. In 2008, he joined the Condensed Matter Theory group at PSI, shifting his research interests to more general forms of structural and magnetic disorder with a focus on bulk metallic glasses, heavily irradiated materials, and spin-ice physics in both two dimensional magnetic meta-materials and bulk pyrochlores. He has been a visiting scientist at the Culham Centre for Fusion Energy, Oxford-UK, and at the Federal Institute of Materials Research and Testing, Berlin-Germany. Since 2019, PD is an adjunct professor within the Materials Department at ETH Zurich.