Publications associées à Taux de cristallinité

Ultrahigh-quality-factor micro- and nanomechanical resonators using dissipation dilution

Tobias Kippenberg, Alberto Beccari, Nils Johan Engelsen

Mechanical resonators are widely used in sensors, transducers and optomechanical systems, where mechanical dissipation sets the ultimate limit to performance. Over the past 15 years, the quality factors in strained mechanical resonators have increased by f ...

Nature Portfolio2024

A continuous-wave and pulsed X-band electron spin resonance spectrometer operating in ultra-high vacuum for the study of low dimensional spin ensembles

Giovanni Boero, Fabio Donati, Soyoung Oh

We report the development of a continuous-wave and pulsed X-band electron spin resonance (ESR) spectrometer for the study of spins on ordered surfaces down to cryogenic temperatures. The spectrometer operates in ultra-high vacuum and utilizes a half-wavele ...

Aip Publishing2024

Atomic scale volume and grain boundary diffusion elucidated by in situ STEM

Johann Michler, Xavier Maeder, Amit Sharma, Laszlo Pethö

Diffusion is one of the most important phenomena studied in science ranging from physics to biology and, in abstract form, even in social sciences. In the field of materials science, diffusion in crystalline solids is of particular interest as it plays a p ...

Nature Portfolio2023

Anomalous topological waves in strongly amorphous scattering networks

Romain Christophe Rémy Fleury, Zhechen Zhang, Pierre Delplace

Topological insulators are crystalline materials that have revolutionized our ability to control wave transport. They provide us with unidirectional channels that are immune to obstacles, defects, or local disorder and can even survive some random deformat ...

2023

Impact of rapid thermal processing on bulk and surface recombination mechanisms in FZ silicon with fired passivating contacts

Christophe Ballif, Franz-Josef Haug, Andrea Ingenito, Audrey Marie Isabelle Morisset, Sofia Libraro, Mario Joe Lehmann

We investigate bulk and interface recombination in crystalline silicon with p-type fired passivating contacts. These consist of a chemical oxide and an in-situ doped layer of SiCx with low carbon content. Following a rapid thermal annealing to activate the ...

ELSEVIER2022

Local excitations in amorphous solids

Wencheng Ji

Amorphous solids are structurally disordered. They are very common and include glasses, colloids, and granular materials, but are far less understood than crystalline solids. Key aspects of these materials are controlled by the presence of excitations in w ...

EPFL2021

Interaction of Confined Polaritons in Microcavity Structures

Morteza Navadeh Toupchi

A polariton is a quasiparticle formed from the coupling of a confined photon in a cavity to electronic excitation, like exciton in a semiconductor. This dissertation reports on series of experiments in confined polariton interaction by design, fabrication, ...

EPFL2021

Optimization of composition and structure of cemented carbide cutting tools

Samy Adjam

WC-Co cemented carbides are composites, which combine a hard phase consisting of WC grains and a metallic ductile phase as a binder. Their excellent mechanical properties, combining high hardness, toughness and refractory properties, make them excellent ma ...

EPFL2021

Tensile and Impact Toughness Properties of a Zr-Based Bulk Metallic Glass Fabricated via Laser Powder-Bed Fusion

Roland Logé, Jamasp Jhabvala, Antonia Neels, Navid Sohrabi, Annapaola Parrilli

In the past few years, laser powder-bed fusion (LPBF) of bulk metallic glasses (BMGs) has gained significant interest because of the high heating and cooling rates inherent to the process, providing the means to bypass the crystallization threshold. In thi ...

MDPI2021

Crystalline Order in Compound Semiconductors in Nanoscale Structures and Thin Films

Mahdi Zamani

Semiconductors materials and devices are essential building blocks for many of the technologies deeply embedded in modern life. Improving the performance of semiconductor devices requires a deeper understanding of the fundamental mechanisms controlling the ...

EPFL2021