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ERC -TIPS

 

The (Nano)Materials for Energy group at ILM participate in a €5.2 million European project on thermally-integrated photonics (TIPS)

The group is a partner in the EU-funded project ‘Thermally Integrated Smart Photonics Systems (TIPS)’, recently awarded under the Horizon 2020 call for Smart Integration Systems.

Widespread usage of mobile devices such as smartphones and tablets to access data-hungry services such as high definition video are already taxing current communications networks, and this data traffic is forecast to grow aggressively over the next five years. The TIPS project will enable photonics devices which are 5x more efficient, resulting in faster optical communications systems, with significantly lower energy consumption, to drive Europe’s growing digital economy.

    

  from Bell Labs.' Thermal Manage. Res. Program, Dublin, Ireland Enright, R., Shenghui Lei ; Nolan, K. ; Mathews, I. ; Shen, A. ; Levaufre, G. ; Frizzell, R. ; Guang-Hua Duan ; Hernon, D.

 

The team is part of a consortium, lead by the Tyndall Institute (Ireland), which includes partners from Germany and the Netherlands – the III-V Lab, University of Hamburg, Alcatel-Lucent Bell Labs Ireland, CNRS Institutes (INL, ILM and IMN), LioniX BV, Alcatel-Lucent Bell Labs France, and Communicraft Ltd.

The team will collaborate closely with the Lyon Institute of Nanotechnology  to create micro-Thermoelectric devices to control the temperature in photonics devices. The consortium as a whole features a multidisciplinary set of specialists in photonic device and system design and packaging, thermoelectric materials, and microfluidics. 
 

The suprising anharmonic damping of Terahertz acoustic waves in a network glass

Valentina Giordano ((Nano)materials and Energy research team), in collaboration with researchers from Grenoble and Italy, has published the paper "Anharmonic damping of terahertz acoustic waves in a network glass and its effect on the density of vibrational states" in Physical Review Letters.

 

Glasses represent nowadays an extremely important class of materials for technological applications. Notwithstanding, many of their properties are still not well understood, and object of a number of investigations. This is the case of the propagation of acoustic waves in disordered materials, whose understanding is fundamental for the explanation of heat propagation in these systems, renowned for their extremely low thermal conductivity.

In this paper, the authors have performed a thorough investigation of phonons propagation in a silicate glass by means of inelastic x-ray scattering as a function of temperature. A silicate glass is a network glass, made of a tridimensional network of covalent bonds. For the first time, the authors have found a strong temperature dependence of the damping of Terahertz acoustic waves, which can be ascribed to the anharmonic interaction between acoustic phonons and the thermal vibrations bath. Anharmonicity becomes more and more important as temperature approaches the glass transition temperature, and strongly affects the vibrational density of states. This result is fundamental for developing a theoretical quantitative description of thermal conductivities in this kind of glasses.

 

http://dx.doi.org/10.1103/PhysRevLett.112.125502

      
         

In honor of Georges Bouzerar

        

Here minicolloque program organized by the Academy of Sciences in honor of George Bouzerar, symposium will be held Tuesday, December 16 amphi Gouy all day.
The guiding principle is "order", "disorder" and "correlation" in the physics of condensed matter (almost all age groups, students are concerned!)


Come !

 

    

Amorphe states under pressure

Denis Machon from Energy Team at ILM has puiblished in en collaboration with english and belgian colleages a review article amorphous states under pressure, in Progress in Material Science.

 

Understand and describe the structures and properties of amorphous states are fundamental issues in the physics of materials. Surprisingly obtain an amorphous is to compress a crystalline solid which, by its nature and pressure conditions, can undergo amorphization under pressure.This phenomenon, known since 1984, is seen in the major materials such as ice and quartz.Dans this review article , the authors provide an update on all the experimental , numerical and theoretical work achieved in the quest a model incorporating all the results on this phenomenon. They also propose to integrate the understanding of this amorphization in a more general context , linking it to phase transitions in liquids and poly- amorphism , transition between amorphous states. The use of thermodynamic tools such as energy landscapes also include pressure effects on protein denaturation ( egg white, for example) in a coherent and unified description.

 

 
 
 

Thermodynamics of nanomaterials

Denis Machon, Lucas Piot, Dimitri Hapiuk and Patrice Mélinon (équipe Energie) have published with colleagues from Lyon, Dijon and Villetaneuse an article entitled Thermodynamics of Nanoparticles: Experimental Protocol Based on a Comprehensive Ginzburg-Landau Interpretation in Nano Letters.

 

Understanding the phase stability in nanomaterials is a fundamental challenge required the development of new applications based on nanotechnology. This innovative study provides a unified description of the thermodynamics and kinetics of phase transitions in nanomaterials. ZnO nanoparticles were studied under pressure. In collaboration with chemists colleagues, synthesis methods have been diversified to study the impact of these on the pressure polymorphism. The authors determined the relevant parameters and proposed a new model based on the Ginzburg-Landau theory of phase transitions to understand these observations. This led them to propose an experimental protocol for the scientific community to obtain reliable and reproducible data and identify new avenues to explore for novel properties.

 

  

 

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