Publications related to Corundum

Additive Manufacturing of Bioinspired Mineral-Based Composites

Biominerals are used by natural organisms for example as structural supports and optical sensors. They are produced from a limited number of elements and under ambient conditions. Nevertheless, they often possess excellent mechanical properties and sometim ...

EPFL2024

Excitonic devices with van der Waals heterostructures: valleytronics meets twistronics

Andras Kis, Fedele Tagarelli, Ahmet Avsar, Alberto Ciarrocchi

2D semiconducting transition metal dichalcogenides comprise an emerging class of materials with distinct properties, including large exciton binding energies that reach hundreds of millielectronvolts and valley-contrasting physics. Thanks to the van der Wa ...

2022

Insights on the role of alumina content and the filler effect on the sulfate requirement of PC and blended cements

Karen Scrivener, Franco Alberto Zunino Sommariva

Understanding the mechanism controlling the sulfate requirement of blended cements is crucial for a successful deployment of these technologies towards a more sustainable industry. Particularly, clarification regarding the role of alumina content on the su ...

Pergamon-Elsevier Science Ltd2022

System and method for removing scalloping and tapering effects in high aspect ratio through-silicon vias of wafers

Edoardo Charbon, Sandro Carrara, Simone Frasca, Rebecca Camilla Leghziel

A method for manufacturing vias in a silicon wafer, the silicon wafer having a crystal orientation, and having a plane that is perpendicular to a surface of the wafer, tilted by 35.26°, the method comprising the steps of providing a mask having ...

2021

Inorganic and Metal-Organic Heterogeneous Catalysts for Hydrogen Energy Applications

Fatma Pelin Uran

The main focus of this thesis is the exploration of inorganic and metal-organic heterogeneous catalysts for hydrogen (H2) energy applications. In particular, we investigated metal nanoparticles (NPs) and metal-organic frameworks (MOFs) for their employment ...

EPFL2021

Pressure Drop and Convective Heat Transfer in Different SiSiC Structures Fabricated by Indirect Additive Manufacturing

Sophia Haussener, Ehsan Rezaei, Alberto Ortona, Maurizio Barbato

The microstructure of porous materials has a significant effect on their transport properties. Engineered cellular ceramics can be designed to exhibit properties at will, thanks to the advances in additive manufacturing. We investigated the heat and mass t ...

ASME2020

Parametric Experimental Study and Design of Experiment Modelling of Sapphire Grinding

Daniel Sage

This study investigates and models the grinding process of single crystal sapphire. Five parameters: the wheel speed, the feed speed, the vertical feed, the ultrasonic assistance and the crystallographic direction were considered via a design of experiment ...

Elsevier2017

Determining the Surface Structure of Silicated Alumina Catalysts via Isotopic Enrichment and Dynamic Nuclear Polarization Surface-Enhanced NMR Spectroscopy

David Lyndon Emsley, Brennan James Walder, Jasmine Viger-Gravel

Isotopic enrichment of Si-29 and DNP-enhanced NMR spectroscopy are combined to determine the detailed surface structure of a silicated alumina catalyst. The significant sensitivity enhancement provided by DNP is vital to the acquisition of multinuclear and ...

American Chemical Society2017

Comparison of apparent activation energies for densification of alumina powders by pulsed electric current sintering (spark plasma sintering) and conventional sintering-toward applications for transparent polycrystalline alumina

Paul Bowen, Michael Stuer, Zhe Zhao, Claude Paul Carry

In the quest for high real in-line transmittances for transparent polycrystalline alumina (PCA), we need defect free processing. One of the biggest advances in producing high density defect free ceramics over recent years has been the advent of spark plasm ...

Materials Research Society2017

Small-scale metal castings, small-scale metal/transparent composite structures and process to produce same

Andreas Mortensen, Yves Bellouard, Raphaël Charvet, Cyril Dénéréaz

The method comprises at least the following steps: - exposing a substrate to focused laser irradiation at a preselected series of locations that trace a subset of the substrate volume that is connected to the surface of the substrate; some subsets of subst ...

2017

Grain boundary complexion and transparent polycrystalline alumina from an atomistic simulation perspective

Paul Bowen, Abhishek Tewari

Transparent alumina is often processed with sintering additives such as, Y, La, and Mg, in order to limit its grain growth at high sintering temperatures. Usually, these additives segregate to the grain boundaries due to their larger cationic size than Al ...

Elsevier2016

Upper critical field, pressure-dependent superconductivity and electronic anisotropy of Sm4Fe2As2Te1-xO4-yFy

László Forró, Andrea Pisoni, Richard Gaal, Bálint Náfrádi, Janusz Andrzej Karpinski, Sergiy Katrych, Péter Szirmai

We present a detailed study of the electrical transport properties of a recently discovered iron-based superconductor: Sm4Fe2As2Te0.72O2.8F1.2. We followed the temperature dependence of the upper critical field by resistivity measurement of single crystals ...

Iop Publishing Ltd2016

Single crystals of superconducting SmFeAsOHx: Structure and properties

László Forró, Andrea Pisoni, Alla Arakcheeva, Richard Gaal, Janusz Andrzej Karpinski, Sergiy Katrych, Ping Huang, Péter Krisztián Matus

We report the synthesis, structure, and superconducting properties of single crystals of SmFeAsOHx. The crystals were grown at high pressure and high temperature using a cubic anvil technique. H-1-NMR studies confirm the presence of H atoms in the samples. ...

Amer Physical Soc2016

Structure and electronic properties of AlCrOxN1-x thin films deposited by reactive magnetron sputtering

Alireza Karimi, Emad Oveisi, Hossein Najafi

In this study, the main attempt is devoted to investigating the microstructure and electronic properties of AlCrOxN1 - x films in a wide range of oxygen concentrations from 0 to 1. These oxynitride films were deposited by pulsed DC magnetron sputtering fro ...

Elsevier Science Sa2014

The strength of ruby from X-ray diffraction under non-hydrostatic compression to 68 GPa

Susannah McGregor Dorfman

Polycrystalline ruby (alpha-Al2O3:Cr3+), a widely used pressure calibrant in high-pressure experiments, was compressed to 68.1 GPa at room temperature under non-hydrostatic conditions in a diamond anvil cell. Angle-dispersive X-ray diffraction experiments ...

Springer2014

Colloidal Processing and Yield Stress Modeling Towards Dry Pressed Green Bodies for Transparent Polycrystalline Alumina

Paul Bowen, Michael Stuer

Colloidal processing is a key aspect in modern ceramic processing but most formulations are found empirically. The need for a better knowledge based design of suspension formulation can be achieved by using interparticle potential modelling linked to rheol ...

Wiley-Blackwell2014

Atomistic Modeling of Processing Issues for Transparent Polycrystalline Alumina

Abhishek Tewari

Transparent polycrystalline alumina has many possible promising areas of application from jewelry and the watch industry to wave guides, energy economical lamp envelopes, and optical windows. Ultrahigh density, submicron sized grains and/or oriented micros ...

EPFL2013

Synthesis, crystal growth and physical properties of the frustrated spin ladder material BiCu2PO6

Shuang Wang

In recent years quantum antiferromagnets with an intrinsically disordered (“spin liquid”) ground state and an energy gap in the spin excitation spectrum have received a great deal of attention. In search for new experimental realizations of spin-ladder and ...

EPFL2013

Formation Mechanisms and Structural Properties of Aluminium-Chromium Based Oxynitride Thin Films Synthesized by Physical Vapor Deposition

Hossein Najafi

Oxynitride thin films, a novel class of mixed anionic solid structures, have gained an intense interest during recent years related to the unique interplay of oxygen (O) and nitrogen (N) with metals in the material structure. This matter can result in spec ...

EPFL2012

Freeze granulation: Powder processing for transparent alumina applications

Paul Bowen, Michael Stuer, Zhe Zhao

Use of freeze granulated powders is successfully used as an industrially viable alternative to loose powder sintering for transparent polycrystalline alumina (PCA). Freeze granulation with narrow granule size distribution was realized after suspension cond ...

2012