Alexandra Delvallee

Alexandra Delvallee
Laboratoire National de Métrologie et d'Essais · Nanometrology

PhD

About

38
Publications
10,412
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272
Citations
Additional affiliations
December 2015 - present
December 2014 - December 2015
Laboratoire National de Métrologie et d'Essais
Position
  • PostDoc Position
February 2011 - December 2014
Laboratoire National de Métrologie et d'Essais
Position
  • PhD Student

Publications

Publications (38)
Article
This article is the first step in the development of a hybrid metrology combining AFM and SEM techniques for measuring the dimensions of a nanoparticle population in 3D space (X,Y,Z). This method exploits the strengths of each technique on the same set of nanoparticles. AFM is used for measuring the nanoparticle height and the measurements along X...
Article
This article reports on the evaluation of an uncertainty budget associated with the measurement of the mean diameter of a nanoparticle (NP) population by Atomic Force Microscopy. The measurement principle consists in measuring the height of a spherical-like NP population to determine the mean diameter and the size distribution. This method assumes...
Article
Scanning Electron Microscopy (SEM) technique is widely used for characterizing nanoparticle (NP) size but very few papers deal with NP dimensional metrology. This article reports on the methodology to evaluate the uncertainty budget associated with the measurement of the mean diameter of standard silica NP population by SEM. In this context, the ef...
Article
Full-text available
At this time, there is no instrument capable of measuring a nano-object along the three spatial dimensions with a controlled uncertainty. The combination of several instruments is thus necessary to metrologically characterize the dimensional properties of a nano-object. This paper proposes a new approach of hybrid metrology taking advantage of the...
Article
Full-text available
In this paper, the accurate determination of the size and size distribution of bipyramidal anatase nanoparticles (NPs) after deposition as single particles on a silicon substrate by correlative Scanning Electron Microscopy (SEM) with Atomic Force Microscopy (AFM) analysis is described as a new measurement procedure for metrological purposes. The kn...
Article
Full-text available
The importance of high dielectric constant materials in the development of high frequency nano-electronic devices is undeniable. Their polarization properties are directly dependent on the value of their relative permittivity. We report here on the nanoscale metrological quantification of the dielectric constants of two high-κ materials, lead zirco...
Article
The morphology of amorphous silica NPs in three dimensions (3D) of space is analysed using a single technique: the transmission electron microscope in Scanning Transmission Electron Microscopy with High Angle Annular Dark Field (HAADF-STEM) imaging mode. For this purpose, a method consisting in adjusting the HAADF-STEM signal by a function describi...
Article
Scanning Electron Microscopy (SEM) technique is widely used to characterize nanoparticle (NP) size. The landing energy (LE) of the primary electron beam is considered to be a key parameter related to the ability of electrons to penetrate the sample. However, few studies have been carried out so far on the influence of this parameter on the measurem...
Article
Full-text available
The size characterization of particles present in the form of agglomerates in images measured by scanning electron microscopy (SEM) requires a powerful image segmentation tool in order to properly define the boundaries of each particle. In this work, we propose to use an algorithm from the deep statistical learning community, the Mask-RCNN, coupled...
Article
Full-text available
Reference samples are commonly used for the calibration and quantification of nanoscale electrical measurements of capacitances and dielectric constants in scanning microwave microscopy (SMM) and similar techniques. However, the traceability of these calibration samples is not established. In this work, we present a detailed investigation of most p...
Article
Full-text available
This paper presents a calibration method and an uncertainty budget for capacitance measurements performed on micrometric size capacitors at microwave frequencies and nanometric resolution using a scanning microwave microscopy (SMM). The method applies the classical one-port vector network analyzer calibration for SMM using three known capacitance s...
Poster
Full-text available
In 2018, LNE’s metrological atomic force microscope (mAFM) performed its very first calibrations on standards developed at LNE (P600H60) in collaboration with C2N (Centre for Nanoscience and Nanotechnology). It provides a French traceability route to the SI meter for dimensional measurement at nanometer scale for calibration of standards commonly u...
Presentation
Full-text available
The presentation will focus on the recent commissioning of the first French metrological atomic force microscope (mAFM), the keystone of a new traceability chain implemented by the French national metrology institute (LNE) for dimensional measurements performed at the nanometre scale.
Conference Paper
The LNE has developed its own metrological atomic force microscope (mAFM) which is now the French reference instrument for the measurement of AFM and SEM standards. This instrument uses four double path differential interferometers to measure the XYZ position of the tip relative to the sample. The measurement uncertainties of the mAFM were evaluate...
Conference Paper
Full-text available
The LNE has developed its own metrological atomic force microscope (mAFM) which is now the French reference instrument for the measurement of AFM and SEM standards. This instrument uses four double path differential interferometers to measure the XYZ position of the tip relative to the sample. The measurement uncertainties of the mAFM were evaluate...
Article
Full-text available
Scanning Electron Microscopy (SEM) is considered as a reference technique for the determination of nanoparticle (NP) dimensional properties. Nevertheless, the image analysis is a critical step of SEM measuring process and the initial segmentation phase consisting in determining the contour of each nano-object to be measured must be correctly carrie...
Poster
Full-text available
Le poster se focalisera sur la récente mise en service du premier AFM métrologique (mAFM) français. Cet instrument de référence développé par le LNE matérialise une nouvelle voie de traçabilité pour les mesures dimensionnelles réalisées à l’échelle nanométrique. Il délivre des mesures directement traçables au mètre SI (Système international d’unité...
Poster
Full-text available
We propose a novel approach of hybrid metrology combining AFM (Atomic Force Microscopy) and SEM (Scanning Electron Microscopy) measurements for measuring the characteristic dimensions of nanoparticles (NP) in 3D with controlled uncertainties. This method takes advantage of the complementary nature of both techniques: SEM gives no quantitative infor...
Poster
Full-text available
Graphene attracts LNE’s interest for more than 10 years as it is today the most promising material to establish a practical traceability for electrical resistance to the quantum Hall effect [1]. Beyond, graphene can have many innovative applications the development of which needs accurate control of the material properties. To support the expected...
Article
A calibration algorithm based on one-port vector network analyzer (VNA) calibration for scanning microwave microscopes (SMMs) is presented and used to extract quantitative carrier densities from a semiconducting n-doped GaAs multilayer sample. This robust and versatile algorithm is instrument and frequency independent, as we demonstrate by analyzin...
Chapter
The development of the nanometrology, science of the measurement at the nanoscale, aims to tackle the issues related to the reliability, the trueness, and the comparability of measurements on nanomaterials. The structure of the traceability chain for dimensional measurements at the nanoscale causes to divide all the relevant techniques for sizing n...
Poster
Full-text available
The French “Club nanoMétrologie”, created in 2011 by LNE and C’Nano (a program initiated by the CNRS, the CEA and the French Ministry of Research), organized by the end of 2013 the very first comparison at the national scale on AFM and SEM measurements of dimensional characteristics of 2D gratings (pitch and height). The aim of this comparison was...
Poster
Full-text available
Nanosciences and Nanotechnologies industrial activities raise new questions in terms of production processes and potential risks associated to the use of nanomaterials. The reliability of measurement data appears as a core issue and stresses the importance of developing metrological traceability to common references (most of the time the Internatio...
Article
This work investigates the aerosols emitted during combustion of aircraft and naval structural composite materials (epoxy resin/carbon fibers and vinyl ester/glass fibers and carbon nanotubes). Combustion tests were performed at lab-scale using a modified cone calorimeter. The aerosols emitted have been characterized using various metrological devi...
Thesis
Les travaux présentés dans ce mémoire portent sur les mesures de tailles de nanoparticules effectuées par Microscopie à Force Atomique (AFM) et Microscopie Electronique à Balayage (MEB). Des méthodes de mesures de taille de nanoparticules sphériques sont présentées pour les deux instruments. Une technique de dépôt mettant en œuvre une tournette et...
Article
Full-text available
We report on the observation of strong backscattering of charge carriers in the quantum Hall regime of polycrystalline graphene grown by chemical vapor deposition, which alters the accuracy of the Hall resistance quantization. The temperature and magnetic field dependence of the longitudinal conductivity exhibits unexpectedly smooth power law behav...
Conference Paper
The commercial products containing nanomaterials are already a part of our everyday life and new products enter the market regularly. But the nanometrology, i.e., science of the measurement at the nanometer scale, is still in its early stages. However, all actors concerned by nanoscience and nanotechnologies in the industrial sector or academic wor...
Article
Full-text available
Both optical and tactile probes are often used in dimensional metrology applications, especially for roughness, form, thickness and surface profile measurements. To perform such kinds of measurements with a nanometre-level of accuracy (~30 nm), Laboratoire National de Métrologie et d'Essais (LNE) has developed a new high-precision machine. The arch...
Article
Full-text available
Depuis plusieurs années, les nanoparticules manufacturées sont destinées à des usages industriels. Afin d’évaluer l’exposition professionnelle aux nanoparticules en suspension dans l’air, il est important de disposer de méthodes de mesure fiables et normalisées à leur caractérisation. Il est donc nécessaire de réaliser en amont des études de pré-no...
Article
Full-text available
Results of an interlaboratory comparison on size characterization of SiO2 airborne nanoparticles using on-line and off-line measurement techniques are discussed. This study was performed in the framework of Technical Working Area (TWA) 34 - "Properties of Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS...
Conference Paper
Full-text available
Using combined AFM ( Atomic Force Microscope) and a SEM (Scanning Electron Microscope) makes it possible to accurately measure a nano-object in 3 dimensions. This paper deals with the traceable measurements of the size and the size distribution of a SiO2 spherical shaped nanoparticle population performed by both microscopy techniques. The complemen...
Article
Full-text available
LNE is developing a MEtrological ChARacterization of Nanomaterials (CARMEN) platform to offer a complete supply of main parameter measurements characterizing a nano-object (size, shape, polydispersity, agglomeration/aggregation state, surface charges, specific charges. . . ). Other physical properties such local electrical measurements will be able...

Questions

Questions (2)
Question
Hi everybody
I’m trying to determine the force applied to a sample when the tip of an AFM working in tapping mode touch intermittently the surface. Does anyone has an idea about this ?
Thank in advance
Alex
Question
I just mention that both instruments are calibrated by using a traceable standard. For AFM, measurements are achieved by estimating the height of nanoparticles whereas for SEM diameter is investigated. In all case, AFM measurements are below the SEM measurements with about 6 nm discrepancy!

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Projects

Projects (6)
Archived project
Project
Metrology of nanoparticles in food, cosmetic, materials.