Publication

Modulated Structures Induced by Phase Transformations

Related publications (59)

Graph Chatbot

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Theoretical Investigation of the Radiation Pattern From LEDs Incorporating Shallow Photonic Crystals

Romuald Houdré

A theoretical approach based on coupled-mode theory is presented in order to determine the radiation pattern of LEDs incorporating a shallow photonic crystal. From this, a fundamental limit for the directionality of the diffraction of a single guided mode ...

2009

Phase diagram of a polariton laser from cryogenic to room temperature

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Eric Feltin, Jacques Levrat, Gabriel Christmann

The signature of the strong-coupling regime is unambiguously evidenced in a GaN-based microcavity (MC) above the polariton lasing threshold P-thr at room temperature through the observation of the upper polariton branch. The MC system exhibits a renormaliz ...

2009

Chromium at high pressures: Weak coupling and strong fluctuations in an itinerant antiferromagnet

Henrik Moodysson Rønnow

The spin- and charge-density-wave order parameters of the itinerant antiferromagnet chromium are directly measured with nonresonant x-ray diffraction as the system is driven toward its quantum critical point with high pressure using a diamond anvil cell. T ...

AMER PHYSICAL SOC2008

Simulations d'une structure cristalline incommensurable à caractère désordonné

Eric Germaneau

Incommensurate crystal structures do not display three-dimensional periodicity. Discovered in the 1960's, a mathematical model has been established in 1974 only. Incommensurate structures belong to the big family of aperiodic structures. The modulation of ...

EPFL2008

MOEMS thermal imaging camera

Muhammed Fatih Toy, Onur Ferhanoglu

A novel thermo-mechanical Infrared (IR) imaging array with integrated diffraction gratings for optical readout was fabricated and tested. Parylene was used as a structural material for its low thermal conductivity and high thermal expansion properties. Tes ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2008

Temperature-induced Phase Transitions in Micro-, Submicro-, and Nanocrystalline NaNbO3

Arnaud Magrez

Phase transitions in micro-, submicro-, and nanocrystalline NaNbO3 were investigated by temperature-tuning Raman spectroscopy and X-ray powder diffraction method. Three powders with different average particle size showed successive phase transitions within ...

2007

Temperature-controlled martensitic phase transformations in a model NiAl alloy

Reversible martensitic phase transformations in a partially disordered Ni-Al alloy within the composition range from 60 to 65 at. % of Ni are investigated using molecular dynamics simulation. During a complete temperature cycle a wide hysteresis in enthalp ...

2006

Phase transitions, anisotropy and domain engineering

Matthew Davis

Relaxor-ferroelectric single crystals PZN-xPT [(1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3] and PMN-xPT [(1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3] continue to attract much interest due to their anomalously large piezoelectric properties (d33 > 2000 pm/V; k33 > 90%) when poled ("do ...

EPFL2006

A reinterpretation of the phase transitions in Na2CO3

Gervais Chapuis, Alla Arakcheeva

Based on the structural data of phases alpha (hexagonal; 756-972 K), beta (monoclinic; 605-751 K), gamma (incommensurate, monoclinic; 295 K) and delta (lock-in, monoclinic; 110 K) of sodium carbonate, Na2CO3, we could draw a parallel between the phase tran ...

2005

Coherent x-ray diffraction from quantum dots

Coherent x-ray diffraction is a new experimental method for studying perfect and imperfect crystals. Instead of incoherent averaging, a coherent sum of amplitudes produces a coherent diffraction pattern originating from the real space arrangement of the sa ...

2005