Publications associées à Platinum based alloys

Surface segregation in high-entropy alloys from alchemical machine learning

Michele Ceriotti, Sandip De, Nataliya Lopanitsyna, Guillaume André Jean Fraux, Arslan Mazitov

High-entropy alloys (HEAs), containing several metallic elements in near-equimolar proportions, have long been of interest for their unique mechanical properties. More recently, they have emerged as a promising platform for the development of novel heterog ...

Iop Publishing Ltd2024

Analysis of accretion disc structure and stability using open code for vertical structure

Pascale Jablonka

Detailed chemical abundances of very metal-poor (VMP; [Fe/H] < -2) stars are important for better understanding the first stars, early star formation, and chemical enrichment of galaxies. Big on-going and coming high-resolution spectroscopic surveys provid ...

OXFORD UNIV PRESS2023

Modelling of metal alloys in realistic conditions with machine learning

Nataliya Lopanitsyna

Computer simulations based on statistical methods have emerged as a powerful tool for studying structure-property relationships at the atomistic level. However, to provide reliable insights into materials in realistic conditions, it is essential to accurat ...

EPFL2023

The Pristine survey - XX. GTC follow-up observations of extremely metal-poor stars identified from Pristine and LAMOST

Pascale Jablonka

A B S T R A C T Ultra-metal-poor stars ( [Fe / H] < -4 . 0) are very rare, and finding them is a challenging task. Both narrow-band photometry and low-resolution spectroscopy have been useful tools for identifying candidates, and in this work, we combine b ...

OXFORD UNIV PRESS2023

Modeling high-entropy transition metal alloys with alchemical compression

Michele Ceriotti, Sandip De, Nataliya Lopanitsyna, Guillaume André Jean Fraux

Alloys composed of several elements in roughly equimolar composition, often referred to as high-entropy alloys, have long been of interest for their thermodynamics and peculiar mechanical properties, and more recently for their potential application in cat ...

AMER PHYSICAL SOC2023

Catalyst Aggregate Size Effect on the Mass Transport Properties of Non-Noble Metal Catalyst Layers for PEMFC Cathodes

Yen-Chun Chen, Vasiliki Tileli, Robin Pierre Alain Girod, Michele Bozzetti, Secil Unsal

Non-noble metal catalysts (NNMCs) are regarded as a promising alternative to the costly Pt-based materials required to catalyze the oxygen reduction reaction (ORR) in proton exchange membrane fuel cell (PEMFC) cathodes. However, the large diversity of NNMC ...

ELECTROCHEMICAL SOC INC2023

Plasmonic effects in the neutralization of slow ions at a metallic surface

Marnik Bercx

Secondary electron emission is an important process that plays a significant role in several plasma-related applications. As measuring the secondary electron yield experimentally is very challenging, quantitative modelling of this process to obtain reliabl ...

WILEY-V C H VERLAG GMBH2023

The Pristine survey - XV. A CHIT ESPaDOnS view on the Milky Way halo and disc populations

Pascale Jablonka, Willem Suter, Carmela Lardo, Romain Ely Roland Lucchesi

We present a one-dimensional, local thermodynamic equilibrium homogeneous analysis of 132 stars observed at high resolution with ESPaDOnS. This represents the largest sample observed at high resolution (R similar to 40 000) from the Pristine survey. This s ...

OXFORD UNIV PRESS2022

A stellar stream remnant of a globular cluster below the metallicity floor

Pascale Jablonka, Carmela Lardo

Stellar ejecta gradually enrich the gas out of which subsequent stars form, making the least chemically enriched stellar systems direct fossils of structures formed in the early Universe(1). Although a few hundred stars with metal content below 1,000th of ...

NATURE PORTFOLIO2022

A ductility criterion for bcc high entropy alloys

William Curtin, Binglun Yin, Eleanor Yi Kei Mak

A current goal driving alloy development is the identification of alloy compositions for high temperature applications but with the additional requirement of sufficient ductility at ambient temperatures. Multicomponent, single-phase, polycrystalline High E ...

PERGAMON-ELSEVIER SCIENCE LTD2021

Atomic scale investigations of fracture in metal alloys

Eleanor Yi Kei Mak

The demand for metal alloys with superior structural performance in industrial applications continues to increase, as does the need for more-energy efficient materials and methods. Many materials that are otherwise attractive for structural applications ar ...

EPFL2021

Laser powder-bed fusion of metallic alloys with enhanced microstructures and properties

Navid Sohrabi

Laser powder-bed fusion (LPBF) is an additive manufacturing (AM) process that uses a laser to selectively melt a powder bed. This process can build dense samples with complicated geometries from a wide variety of metallic alloys. In this thesis, LPBF of al ...

EPFL2021

The Pristine Inner Galaxy Survey (PIGS) III: carbon-enhanced metal-poor stars in the bulge

Pascale Jablonka, Carmela Lardo

The most metal-deficient stars hold important clues about the early buildup and chemical evolution of the Milky Way, and carbon-enhanced metal-poor (CEMP) stars are of special interest. However, little is known about CEMP stars in the Galactic bulge. In th ...

OXFORD UNIV PRESS2021

Understanding Thermomechanical Treatments Induced by Laser Powder Bed Fusion Process

Hossein Ghasemi Tabasi

Additive Manufacturing (AM) is referred to technologies that produce directly 3D parts in a layer-by-layer fashion. Laser Powder Bed Fusion (L-PBF) is one of the most important AM processes, enabling production of very complex metallic objects from a compu ...

EPFL2021

Universal Strategy of Bimetal Heterostructures as Superior Bifunctional Catalysts for Electrochemical Water Splitting

Pengzuo Chen, Yun Tong

Utilizing earth-abundant metals to design economical and efficient electrocatalysts for cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) is critical for acquiring clean hydrogen energy by the electrochemical overall wat ...

AMER CHEMICAL SOC2021

APT/TEM characterization of the element segregation in ferritic/martensitic steels after irradiation in SINQ

Lijuan Cui

Ferritic /martensitic (FM) steels are among the most important materials in various nuclear applications. As radiation-induced segregation (RIS) is one of the major factors for embrittlement of nuclear materials, thereofre it is essential to study the RIS ...

EPFL2021

Stable Palladium Oxide Clusters Encapsulated in Silicalite-1 for Complete Methane Oxidation

Oliver Kröcher, Davide Ferri, Olga Safonova, Teng Li

Zeolite-supported metal catalysts are widely employed in a number of chemical processes, and the stability of the catalytically active species is one of the most critical factors determining the reaction performance. A good example is the Pd/zeolite cataly ...

AMER CHEMICAL SOC2021

Homogeneity in the early chemical evolution of the Sextans dwarf spheroidal galaxy

Pierre North, Pascale Jablonka, Carmela Lardo, Romain Ely Roland Lucchesi

We present the high-resolution spectroscopic analysis of two new extremely metal-poor star (EMPS) candidates in the dwarf spheroidal galaxy Sextans. These targets were preselected from medium-resolution spectra centered around the CaII triplet in the near- ...

EDP SCIENCES S A2020

Solidification of Metallic Alloys: Does the Structure of the Liquid Matter?

Michel Rappaz, Güven Kurtuldu

In 1952, Frank (Proc R Soc Lond Ser-Math Phys Sci 215:43-46, 1952) already postulated that Icosahedral Short Range Order (ISRO) of atoms in the liquid could possibly explain the large nucleation undercoolings measured in metallic alloys by Turnbull and Fis ...

SPRINGER2020

Electrochemical reconstruction of ZnO for selective reduction of CO2 to CO

Andreas Züttel, Kun Zhao, Wen Luo, Emanuele Moioli, Jie Zhang, Qin Zhang

Electrocatalytic conversion of CO2 to valuable chemicals is a highly promising route to close the carbon cycle. Herein, Zn catalysts derived from electrochemical reconstruction of ZnO materials are presented as efficient CO2-to-CO catalysts. We found that ...

2020