Dense structures on the nanoscale – DENSE

Defining matter characteristics at structural levels is key in designing materials and functions. To this, extreme conditions of pressure and temperature are favorable to synthesize novel extraordinary phases. We focus here on the achievement, optimization and characterization of extreme states with record thermodynamic parameters (TPa, 10^5K) and evolution controllable in space and time, toward new metastable mesoscopic phases and superdense materials. DENSE project proposes an innovative technique to create new material structures and high density structural packing in fused silica and related materials (hard materials and geo-chronometer minerals), from high density vitreous phases to new crystalline forms. This is based on ultrafast laser-induced extreme conditions confined in a nanoscale solid volume as means for novel material phases and polymorphs. The concept exploits the combination of strong non-equilibrium, extremely high electronic pressure levels and fast quenching rates to determine novel structural arrangements resulting of high compaction rates and unusual thermodynamic trajectories and asses their properties, notably mechanical characteristics. Thus the project aims to acquiring a significant body of knowledge in a rather unexplored domain which can have a high interest. The technique involves the use of engineered beams and non-diffractive geometries that can lead to innovative compaction designs and unprecedented levels of energy confinement. Multiscale quantitative observation techniques are proposed to map in time matter evolution, with potential to identify the transformation drives and to elucidate displacive or nucleated character of synthesis. Mechanical properties of new structural forms will be evaluated using innovative micro/nano-mechanical tests to assess the mechanical performance of these phases in relation to their structure. Thus, combining ultrafast non-equilibrium and strong thermo-mechanical constraints, we aim at identifying the drive forces using space-time design of irradiation sources, dynamic observation of structural dynamics, simulation of novel phases and assessment of their mechanics. We expect significant knowledge gain in understanding material behaviors in extreme conditions and strong deformation yields and in the realization of extraordinary compacted phases. Application of these techniques to silica materials for generating high-pressure phases carries not only a strong technology potential (with a specific interest in the mechanics of dense phases) but equally a fundamental interest as marker in geophysical high-energy interactions To this end DENSE proposed a multidisciplinary consortium that has extensive expertise in laser beam engineering, probing laser phenomena, simulation of material transformation, glassy materials, electronic and structural characterization skills, and mechanical assessment, to optimally respond to the challenges raised by the project. The strategy aims at developing efficient irradiation geometries, in-situ observation methods, predictive simulation and characterization methods with deep insight into the physics of the structural drive. The question refers to upgrading energy deposition to record levels, validating transformation scenarios based on dynamic evolution, structurally understanding materials and their metastability and evaluation their mechanical properties.