Raynald Gauvin

Raynald Gauvin
McGill University | McGill · Department of Mining and Materials Engineering

Ph.D.

About

509
Publications
51,731
Reads
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5,971
Citations
Citations since 2016
182 Research Items
3799 Citations
20162017201820192020202120220200400600
20162017201820192020202120220200400600
20162017201820192020202120220200400600
20162017201820192020202120220200400600
Additional affiliations
July 2001 - present
McGill University
July 1990 - July 2001
Université de Sherbrooke

Publications

Publications (509)
Article
Solid state electrolytes represent an attractive alternative to liquid electrolyte in rechargeable batteries. However, the fabrication of batteries with ceramic materials requires high temperature that could be detrimental to their electrochemical performance. In this work we show that it`s possible to densify garnet-type Li5La3Bi2O12 solid electro...
Article
Full-text available
Coatings containing silver (Ag) as a solid lubricant are used in a wide variety of applications. These are usually produced by physical vapor deposition (PVD) or by thermal spray, and silver reportedly act reducing friction when tested at temperatures up to 400 °C. The mechanisms of solid lubrication of silver in these PVD coatings are well underst...
Article
This paper will present state of the art characterization of Lithium Ion Batteries usimg low voltage EELS and EDS of Li using the SU-9000 STEM from Hitachi working at 30 keV and 3 keV. Extensive in-situ work in SEM of LIB made with Li anodes will also be presented.
Article
This work reports the growth of graphene nanobuds (GNB) on Cu foil by chemical vapor deposition and its direct application as an electrode in lithium-ion batteries. The obtained novel GNB anode exhibited a superhigh specific capacity of 2813 mAh g⁻¹ at a current rate of 4 A g⁻¹ with a reversible coulombic efficiency of 78% in the first cycle. The m...
Article
A novel approach, termed line-rotated remapping (LRR), for high resolution electron backscatter diffraction is proposed to remap patterns with large rotation. In LRR, the displacements during the first-pass cross-correlation is modified to a function of the corresponding Kikuchi lines and the points on the reference pattern. Then, the finite rotati...
Article
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Quantitative microanalysis of rough surfaces is difficult in the scanning electron microscope. Although X-Ray microanalysis can be a useful tool for preliminary characterization, it is not quantitative because the complicated geometry of the rough surface introduces problems that are not present in the current models of quantitative microanalysis o...
Article
Titanium-based biomaterials are the gold standard for orthopedic implants; however, they are not generally suitable for the manufacture of intravascular stents. Their low strength-ductility trade-off and low work hardening rate are their main limitations. However, Ni-free alloys are desirable for such application in order to avoid allergic reaction...
Article
Climate change, population growth, and rising fossil fuel prices have encouraged governments and scientists for alternate energy resources. This energy transition requires a high-performance energy storage device to satisfy the high energy and power demand and lithium-ion battery (LIB) is one of the promising one. The performance of these batteries...
Article
Scanning electron microscopy (SEM) equipped with an energy dispersive spectroscopy (EDS) is one of the most popular microanalytical techniques for image characterization and X-ray microanalysis. A low-voltage SEM/EDS analysis offers numerous advantages; however, there are still many challenges in data acquisition and interpretation. New computation...
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In the past few decades, nanostructured carbons (NCs) have been investigated for their interesting properties, which are attractive for a wide range of applications in electronic devices, energy systems, sensors, and support materials. One approach to improving the properties of NCs is to dope them with various heteroatoms. This work describes the...
Article
An in situ monoclinic variants selection and rearrangement study on Y2O3‐ZrO2 coatings was conducted using electron backscattered diffraction. The sequence growth of variants with the correspondence of (100)m ∼// (010)t, [010]m ∼// [001]t, and [001]m ∼// [100]t (CAB‐OR2) was found initially and converted to the 90° rotated sequence growth with (100...
Article
Generating quantitative phase maps is unvaluable to access the phase distribution in a material. X-ray hyperspectral mapping using an energy dispersive spectrometer (EDS) attached to a scanning electron microscope (SEM) is the most practical way to collect these data, mainly due to its relatively ease of operation and availability around the world....
Article
Scanning electron microscopy (SEM) produces images at 500000 times magnification and better than 1nm resolution to characterize inorganic and organic solid morphology, surface topography, and crystallography. An electron beam interacts with the material and generates secondary electrons (SE) and backscattered electrons (BSE) that detectors capture....
Article
Focused ion beam (FIB) tomography is a destructive technique used to collect three-dimensional (3D) structural information at a resolution of a few nanometers. For FIB tomography, a material sample is degraded by layer-wise milling. After each layer, the current surface is imaged by a scanning electron microscope (SEM), providing a consecutive seri...
Article
Silicon-doped carbon nanotubes (Si-CNT) have been produced and modified in situ through substitutional silicon doping in the carbon network in one step by a modified chemical vapor deposition (M-CVD) process. Toluene, ferrocene, and triphenylsilane were used as carbon sources, the metal catalyst for the nanotubes' growth, and Si doping agent, respe...
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Full-text available
This work summarizes the most commonly used in situ techniques for the study of Li-ion batteries from the micro to the atomic level. In situ analysis has attracted a great deal of interest owing to its ability to provide a wide range of information about the cycling behavior of batteries from the beginning until the end of cycling. The in situ tech...
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Monte Carlo simulations were performed to investigate the behavior of the peak to background ratio (P/B) of particles on a substrate as a function of different variables such as take-off angle, tilt angle, particle size, and beam energy. The results showed that the P/B highly depends on the beam energy, the size of particles, and the composition of...
Article
The f-ratio method is a new quantitative X-ray microanalysis method developed based on a cold field emission scanning electron microscope/energy dispersive spectroscopy system. The f-ratio is calculated with the characteristic X-ray intensities, and the Monte Carlo simulation is employed to build the theoretical relation between the system composit...
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Full-text available
The microstructures of quenched and tempered steels have been traditionally explored by transmission electron microscopy (TEM) rather than scanning electron microscopy (SEM) since TEM offers the high resolution necessary to image the structural details that control the mechanical properties. However, scanning electron microscopes, apart from provid...
Article
In the last decades, biomaterials have improved the life and its quality for millions around the Globe. Titanium-based biomaterials have rapidly become the gold standard for bone contact applications. Despite their successful performance, their low strength-ductility trade-offs and work-hardening rates limit their use for example for the manufactur...
Article
Arsenic water pollution is a serious global environmental issue because of the high toxicity of this chemical element. Hence, the development of versatile materials that can efficiently remove different arsenic species from water is a global challenge. In this study, the bi-functionality of anatase TiO2 nanostructures (nanoparticles (TNP) and nanot...
Article
While a key reaction for oil upgrade, the hydrogenation of arenes substrates remains a challenging one, requiring the use of transition-metal catalysts and harsher reaction conditions than classic hydrogenation processes. We designed a photocatalyst by deposition of Ru clusters onto plasmonic Au nanoparticles to accelerate this reaction, as well as...
Article
A method of calculating the magnitude of the core hole screening of lithium materials is implemented for the simulation of Energy Loss Near Edge Structure (ELNES). ELNES is calculated for a range of lithium materials resulting in improved agreement between calculation and experiment. The technique uses linear response theory to relate the electron...
Article
In this paper, electrophoretic deposition (EPD) is shown to promote nanoscale assembling of graphene oxide (GO) enabling the fabrication of highly homogeneous, robust, and capacity fade resistant composite titanium niobate (TiNb2O7, TNO)/rGO anodes upon reductive annealing. Control tests revealed that EPD is superior to conventional PVDF-based cast...
Article
Electron tomography has been widely applied to three-dimensional (3D) morphology characterization and chemical analysis at the nanoscale. A HAADF-EDS bimodal tomographic (HEBT) reconstruction technique has been developed to extract high resolution element-specific information. However, the reconstructed elemental maps cannot be directly converted t...
Article
Full-text available
Dendrite formation, which could cause a battery short circuit, occurs in batteries that contain lithium metal anodes. In order to suppress dendrite growth, the use of electrolytes with a high shear modulus is suggested as an ionic conductive separator in batteries. One promising candidate for this application is Li7La3Zr2O12 (LLZO) because it has e...
Article
Full-text available
In this study, the effect of Scanning Electron Microscopy (SEM) parameters such as magnification (M), accelerating voltage (V), and working distance (WD) on the 3D digital reconstruction technique, as the first step of the quantitative characterization of fracture surfaces with SEM, was investigated. The 2D images were taken via a 4-Quadrant Backsc...
Article
Current quantitative X-ray microanalysis methods are only available for homogeneous materials. This paper presents a newly developed inverse modeling algorithm to determine both the structure and composition of two-dimensional (2D) heterogeneous materials from a series of X-ray intensity measurements under different beam energies and beam positions...
Article
Low-voltage STEM-EELS Quantification for Beam Sensitive Material Characterization - Nicolas Dumaresq, Nicolas Brodusch, Raynald Gauvin
Article
Improving the Energy Resolution of Energy Dispersive Spectrometers(EDS) Using Richardson–Lucy Deconvolution - Nicolas Brodusch, Raynald Gauvin
Article
Is a 30 kV CFE-SEM in STEM-in-SEM Mode Suitable for Characterizing Real Materials? - Nicolas Brodusch, Raynald Gauvin
Article
Full-text available
Secondary Fluorescence Correction for Quantitative X-ray Microanalysis Integrated in a User-Friendly Framework - Yu Yuan, Hendrix Demers, Samantha Rudinsky, Nicolas Brodusch, Mathieu Gendron, Eric Yen, Sabrina Clusiau, Nicolas Piché, Raynald Gauvin
Conference Paper
Extract High Resolution 3D Quantitative Elemental Map Using a Combined HAADF-STEM and EDS Tomography - Yu Yuan, Nicolas Brodusch, Frédéric Voisard, Boris Nijikovsky, Audrey Moores, Raynald Gauvin
Article
Direct photo-to-chemical energy conversion realized through photocatalysis could provide the ultimate solution to the intermittency problem of solar energy. Among different designs of photocatalytic solar energy storage systems, the two-electrode system offers the simplest configuration for enabling highly integrated solar energy conversion and sto...
Article
In electron probe microanalysis or scanning electron microscopy, the Monte Carlo method is widely used for modeling electron transport within specimens and calculating X-ray spectra. For an accurate simulation, the calculation of secondary fluorescence (SF) is necessary, especially for samples with complex geometries. In this study, we developed a...
Article
Accurate elemental quantification of materials by X-ray detection techniques in electron microscopes or microprobes can only be carried out if the appropriate mass absorption coefficients (MACs) are known. With continuous advancements in experimental techniques, databases of MACs must be expanded in order to account for new detection limits. Soft X...
Article
The electric energy revolution is driven by battery technology. New chemistries and control systems enables the widespread use of portable electric devices, such as phones, computers, power tools and automobiles. The upward trend in battery performance relies on continuous research[1]. Scanning transmission electron microscopy (STEM) is a commonly...
Article
In material sciences, in order to develop new compounds with different electrical, mechanical or optical properties we need to understand the link between these properties and the microstructure of the material. This apply also to understand the decrease of efficiency of a battery after multiple charge-discharge cycle where the structural changes n...
Article
Lithium-ion batteries are extensively used to transform chemical energy into the electrical energy and vice versa. These batteries are inevitably the best candidates for portable devices such as mobile phones, laptops and specially in the fast-growing market of electrical automobiles. The performance of these batteries is strongly connected to the...
Article
Full-text available
Ti6Al4V coatings were made from spherical and irregular powders manufactured using plasma gas atomization and Armstrong processes, respectively. The coatings, made from the two different powders, were distinctly different in terms of porosity content and hardness. Sliding wear tests were performed at different normal loads on both Ti6Al4V coatings....
Article
Calculations of quantum trajectories associated to a propagated wave function provide new insight into quantum processes such as particle scattering and diffraction. Here, hydrodynamic calculations of electron beam imaging under conditions comparable to those of a transmission electron microscope display the mechanisms behind different commonly inv...
Article
Lithium iron silicate Li2FeSiO4 (LFS) has received significant attention as Li-ion intercalation cathode material. However, it exhibits relatively poor Li-ion intercalation kinetics. In this work, mechanochemically annealed low-temperature orthorhombic (βII, Pmn21) [email protected] nanocomposite is shown to exhibit unusual Li-ion intercalation act...
Article
Silicon doped multiwalled carbon nanotubes (Si-CNT) were synthesized by a modified chemical vapor deposition method, using toluene as carbon source, ferrocene as metal catalyst and triphenylsilane to provide the dopant atoms. The effect of synthesis temperature and concentration of Si-containing precursor on the microstructural properties were stud...
Article
Full-text available
The scanning electron microscope/X-ray energy dispersive spectrometer (SEM/EDS) system is widely applied to rare earth minerals (REMs) to qualitatively describe their mineralogy and quantitatively determine their composition. The performance of multivariate statistical analysis on the EDS raw dataset can enhance the efficiency and the accuracy of p...
Article
Precipitation hardenable Ni-based superalloy Rene 41, considered to have moderate weldability, was produced by laser powder bed fusion (LPBF). Crack-free and dense parts were obtained directly from processing. Parts were characterized in both as-built condition and after aging heat treatment. In the as-deposited condition, scanning electron microsc...
Article
Platinum has been proved to be the most effective electrocatalyst for oxygen reduction reaction (ORR) in proton-exchange membrane (PEM) fuel cells; however, it presents some disadvantages such as its scarcity and, consequently, high cost. Recently, the development of electrocatalysts has been directed towards designing low Pt or Pt free materials....
Article
Full-text available
Lithium metal is a favorable anode material in all-solid Li-polymer batteries because of its high energy density. However, dendrite formation on lithium metal causes safety concerns. Here we obtain images of the Li-metal anode surface during cycling using in situ scanning electron microscopy. Constructing videos from the images enables us to monito...
Article
A serious limitation in the use of energy dispersive spectrometers (EDS) for materials characterization arises from the fact that these x-ray detectors provide a poor energy resolution compared to other x-ray techniques. This is mainly due to the broadening function generated by the electronics of the detector. However, new windowless detectors are...
Article
Achieving aggregation-free nanocomposites is a challenge for the conventional casting process in Li-ion battery electrode fabrication, which leads to inhomogeneous dispersion of active and conductive components – a property which further accelerates, or triggers, battery degradation. This becomes even more challenging when using 2D nanomaterials. I...
Article
Li metal batteries suffer from dendrite formation which causes short circuit of the battery. Therefore, it is important to understand the chemical composition and growth mechanism of dendrites that limit battery efficiency and cycle life. In this study, in situ scanning electron microscopy was employed to monitor the cycling behavior of all-solid L...
Article
Cu2ZnSnS4 or kesterite and its selenium alloyed counterparts are considered promising for next generation photovoltaic applications due to their excellent optoelectronic properties and earth-abundant, non-toxic composition. In order to alleviate the adverse effects of defects and interfaces on charge separation and transport in current thin film ke...
Article
Full-text available
Using Deep Learning to Deconvolute Complex Spectra for Hyperspectral Imaging Applications - Volume 25 Supplement - Samantha Rudinsky, Yu Yuan, Francis B. Lavoie, Raynald Gauvin, Ryan Gosselin, Nadi Braidy, Nicolas Piché, Mike Marsh
Article
Full-text available
Extending Monte Carlo Simulations of Electron Microscopy Images and Hyperspectral Images in a User-Friendly Framework - Volume 25 Supplement - Samantha Rudinsky, Yu Yuan, Raynald Gauvin, Nicolas Piché, Mike Marsh
Article
The Impact of Phase on Mass Absorption Coefficients Using Soft X-ray Emission Spectrometry - Volume 25 Supplement - Samantha Rudinsky, Colin M. MacRae, Nicholas C. Wilson, Hendrix Demers, Raynald Gauvin
Article
Full-text available
EELS Monitoring of Beam-Induced Dynamic Transformation of Lithium Materials at 30 keV - Volume 25 Supplement - Frédéric Voisard, Hendrix Demers, Nicolas Brodusch, Michel L. Trudeau, Karim Zaghib, Raynald Gauvin
Preprint
Full-text available
Calculations of propagating quantum trajectories associated to a wave function provide new insight into quantum processes such as particle scattering and diffraction. Here, hydrodynamic calculations of electron beam imaging under conditions comparable to those of a scanning or transmission electron microscope display the mechanisms behind different...
Article
Full-text available
High-density crack-free Inconel 738 samples were manufactured into both thin-walled and bulk samples using pulsed laser powder bed fusion (P-LPBF). As-built thin-walled samples presented a dendritic microstructure with primary dendrite arm spacing (PDAS) of 1.02 ± 0.21 µm. This PDAS was consistent along the length of the as-built wall, which led to...
Article
A technique to characterize the native passivation layer (NPL) on pure lithium metal foils in a scanning electron microscope (SEM) is described in this paper. Lithium is a very reactive metal, and consequently, observing and quantifying its properties in a SEM is often compromised by rapid oxidation. In this work, a pure lithium energy-dispersive x...