Matthieu Micoulaut, Professor at UPMC, Paris

ANR projects

Programme Blanc ANR Phasabinit (2009-2013)

Atomic scale foundation of a new phase in glasses and related liquids
with C. Massobrio (IPCMS Strasbourg) and P. Simon (CEMHTI Orléans)
 
It has been observed that glasses display a number of remarkable properties in selected compositional windows, the more notable being a stress-free character resulting in the near absence of aging of many physical properties. These compositional windows define a new phase (an intermediate phase, IP) whose origins still remain to be elucidated. It can be neither predicted nor fully understood on the basis of the mean field ideas, since the interplay between statistical mechanics, chemical bonding and macroscopic behaviour is out of reach of simplified approaches.
Our project aims at describing structural and vibrational features of the intermediate phases of prototypical glasses by using First Principles Molecular Dynamics (FPMD) within density functional theory.
The occurrence of the IP is a very general phenomenon that can be observed in both binary and ternary glasses. Since a large number of results have been collected on glasses containing more than two elements, focus is made on representative binary glasses and on one of its ternary counterparts.
PHASABINIT Web page

Programme Blanc ANR Team (2012-2015)

New functionalities of tellurium based amorphous materials
with A. Pradel (ICG Montpellier), C. Bichara (CINAM Marseille) and M.V. Coulet (MADIREL Marseille)
 
Amorphous telluride thin films are now present as starting material in many electronic devices and setups, and found huge applications in the phase change memory (DVD) industry. In order to design new material functionalities for (other) future applications such as improved infrared transmitting waveguides or stable phase change data storage, there is a demanding need to understand in more detail the underlying factors which control the glass-forming tendency of tellurides and the relationship between structure and functional properties. In contrast with light chalcogenides (selenium and sulphide) however, tellurides do not form easily bulk glasses due, in part, to a high crystallization tendency and a difference in chemical bonding.
This project proposes to address such issues by combining molecular simulations, topological modeling, synthesis and characterization of three important families of telluride glasses, with a special emphasis on compositional trends of physical and chemical properties. The chosen alloys belong to the binary Ge-Te and the ternary Ge-Sb-Te systems since they are good candidates for phase change memory and infrared transmitting waveguides.
TEAM Web page

Programme Blanc ANR Electrolith (2010-2014)

In search of carbonate melts in the Mantle by combination of geophysics, laboratory, theory
with F. Gaillard (ISTO Orléans), B. Guillot, N. Sator (LPTMC) and others
 
First-principle molecular dynamics simulations are performed on carbonate systems (CaCO3, Li2CO3,...) at different temperatures and densities. These systems are present in the Earth Mantle and their properties are not very well understood, in particular with respect to the well-documented properties of silicate melts. Such simulations are used to improve the methodology in connection with the establishment of force fields, allowing for increased information on structural, vibrational and electronic properties prior to an investigation of the thermodynamic phase diagram from classical simulations.