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Grenoble, France

The Grenoble Institute of Technology is a French technological university system consisting of six engineering schools.Grenoble INP also has a 2 year preparatory class programme, an adult education department, as well as 35 laboratories and a graduate school in Engineering science. More than 1,100 engineers graduate every year from Grenoble INP, making it France's biggest grande école.Most of Grenoble INP is located in Grenoble, except for the ESISAR which is located in Valence. Wikipedia.


Consonni V.,Grenoble Institute of Technology
Physica Status Solidi - Rapid Research Letters | Year: 2013

GaN nanowires, also called nanocolumns, have emerged over the last decade as promising nanosized building blocks for a wide variety of optoelectronic devices. In contrast to other III-V semiconductors, GaN nanowires have the ability to grow catalyst-free within the self-induced approach by plasma-assisted molecular beam epitaxy, which does not require the use of any foreign materials or patterned substrate. The self-induced growth has accordingly been considered as a valuable growth mode to form GaN nanowires on a wide number of substrates such as Si, Al2O3, diamond or SiC. The formation mechanisms have extensively been investigated and are specifically reviewed here from the very onset of the nucleation phase through the elongation phase to the coalescence process. A general approach of the self-induced growth of GaN nanowires is gained. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Dufresne A.,Grenoble Institute of Technology
Materials Today | Year: 2013

Owing to the hierarchical structure of cellulose, nanoparticles can be extracted from this naturally occurring polymer. Multiple mechanical shearing actions allow the release of more or fewer individual microfibrils. Longitudinal cutting of these microfibrils can be achieved by a strong acid hydrolysis treatment, allowing dissolution of amorphous domains. The impressive mechanical properties, reinforcing capabilities, abundance, low density, and biodegradability of these nanoparticles make them ideal candidates for the processing of polymer nanocomposites. With a Young's modulus in the range 100-130 GPa and a surface area of several hundred m2 g-1, new promising properties can be considered for cellulose. © 2013 Elsevier Ltd. Source


De Boissieu M.,Grenoble Institute of Technology
Chemical Society Reviews | Year: 2012

We review some of the results obtained for the study of phason, phonon and atomic dynamics in quasicrystals. In the framework of the hydrodynamic theory long-wavelength phason modes are characteristic of quasicrystal and are diffusive modes. Quenched-in phason mode gives rise to a characteristic diffuse scattering, observed in all the 'stable' icosahedral quasicrystals studied so far. In the AlPdMn icosahedral phase, above T = 500 °C, equilibrium phason modes are shown to be diffusive modes in agreement with the hydrodynamic theory. The lattice dynamics has been studied by inelastic neutron or X-ray scattering. Well defined acoustic modes are only observed for wavevectors smaller than 0.3 Å -1. Above this value, the mode rapidly broadens as a result of mixing with higher energy modes. We show that the results can be interpreted using the concept of pseudo-Brillouin zone boundary and can qualitatively explain the differences observed in the response function of the ZnSc 1/1 approximant and its quasicrystalline counterpart. The observations are qualitatively and quantitatively reproduced using oscillating pair potentials, which open the route for a detailed analysis of the lattice dynamics at the atomic scale. An exceptional dynamical flexibility is also evidenced in the 1/1 approximant. A brief discussion on the implication of those results on the stabilizing mechanisms of quasicrystals is given at the end of the paper. © 2012 The Royal Society of Chemistry. Source


Controlling ferromagnetic/antiferromagnetic blocking temperatures in exchange biased based devices appears crucial for applications. The blocking temperature is ascribed to the ability of both antiferromagnetic grains and interfacial spin-glass-like phases to withstand ferromagnetic magnetization reversal. To better understand the respective contributions of grains versus spin-glass, blocking temperature distributions were measured after various thermal treatments for cobalt/iridium-manganese bilayers. The high-temperature contribution linked to antiferromagnetic grains shifts towards lower temperatures above a threshold thermal annealing. In contrast, the occurrence and evolution of training effects for the low-temperature contribution only agree with its inferred interfacial spin-glass-like origin. © 2013 American Institute of Physics. Source


Proville L.,CEA Saclay Nuclear Research Center | Rodney D.,Grenoble Institute of Technology | Marinica M.-C.,CEA Saclay Nuclear Research Center
Nature Materials | Year: 2012

Crystal plasticity involves the motion of dislocations under stress. So far, atomistic simulations of this process have predicted Peierls stresses, the stress needed to overcome the crystal resistance in the absence of thermal fluctuations, of more than twice the experimental values, a discrepancy best-known in body-centred cubic crystals. Here we show that a large contribution arises from the crystal zero-point vibrations, which ease dislocation motion below typically half the Debye temperature. Using Wigner's quantum transition state theory in atomistic models of crystals, we found a large decrease of the kink-pair formation enthalpy due to the quantization of the crystal vibrational modes. Consequently, the flow stress predicted by Orowan's law is strongly reduced when compared with its classical approximation and in much closer agreement with experiments. This work advocates that quantum mechanics should be accounted for in simulations of materials and not only at very low temperatures or in light-atom systems. © 2012 Macmillan Publishers Limited. All rights reserved. Source

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