The STEM Group is a french world leading electron microscopy group, specialising in
electron energy loss spectroscopy (EELS). Our scientific interests are large, and are including different parts of the physics and material sciences: nanotubes, nanoparticles, interfaces, nanophotonic... We are constantly develloping instrumentation and methods in the fields of electron microscopies and spectroscopies. We are always interested in new academic
and industrial partners, contact us via the link on the right menu.
jCarousel Examples
Significant Facts:
Post Doc position opening
We are opening a 2 years Post doc position on STEM-EELS atomic and electronic characterization of ferroelectrically-controlled magnetic tunnel junctions. We are seeking motivated candidates: please read the full description of the position and contact us!
Chemical Imaging at Atomic Resolution To Refine the Local Structure of Nanocrystals
Ce2Zr2O8 nanocrystals are characterized by aberration-corrected electron microscopy, core-loss electron energy-loss spectroscopy, and simulations. Direct chemical evidence of an ordered cation sublattice in nanosized (20–30 nm) crystallites is found for the first time. Local deviations in the chemical composition are also detected, with Zr occupying Ce sites (see scheme). (S. Trasobares et al., Angw. Chem. (2011))
Correlating structure and optical emission of nanometric Quantum Emitters
We have measured the cathodoluminescence of individual GaN quantum discs embedded in GaN/AlGaN nanowires. The measured sizes of the individual QDiscs, which could be as small as 1 nm (4 monolayers) were correlated one to one to their emission wavelengths, showing a marked Quantum confined Starck effect and a clear effect of the local strain on the optical properties of QDiscs. The results just appeared in (L. F. Zagonel et al., Nano Letters (2011))
Spectral Imaging of Individual Split Rings Resonnators
We have measured the plasmonic eigenfunctions and eigenmodes of individual Split Ring Resonnators, which form a paradigmatic class of photonic atoms. (G. Boudarham et al., Phys. Rev. Lett. (2010))
Ferroelectric Control of Spin Polarization - Structural investigations at the atomic scale
Check out how atomic structure determination of interfaces of an artificial
multiferroic heterostructure helped in understanding the ferroelectric Control of Spin recently published in Science by Garcia et al....
The STEM group is organizing the conferene "past, present and future of (S)TEM and its application: a tribute to the work of Christian Colliex" in honour of C. Colliex.
Christian Colliex is the 2009 recipient of the Holweck Medal and Prize for his pioneering use of the electron microscope to further our understanding of the electronic structure of nanomaterials.
Electron diffraction and Resonant Raman Experiments on individual nanotubes
We have investigated the structural, vibrationnal and optical properties of individual carbon nanotubes and individual bundles of carbon nanotubes. See how carbon nanotubes couples mechanically and electromagnetically in A. Débarre et al., PRL (2008)
The UltraSTEM has been officially opened, in presence representative of the CNRS, the university, the region, the department, NION and many scientists!
We have developed a new approach to shaping
nanomaterials atom by atom, using a scanning electron microscope as a
nanometrically precise cutting tool. In this way we carved the
materials, such as carbon nanotubes, by removing individual atoms from
specifically chosen locations [Physical Review B, 77 045410].
We have shown that the graphite/h-BN phase separation within single-walled nanotubes can be tailored
within a single layer and we have developed a direct synthesis route
to a new kind of single-walled nanotubes made of graphene and BN
pieces self-organized in a sequential manner along the tube axis.
Thus, combining BN and C elements into one-dimensional nanotubular
systems can open the way to a broad range of nanodevices engineering
and of fundamental research..
Whew! an An ESTEEM-sponsored event organized at Orsay has now ended! Thanks to all participants, students, lecturers and other people who helped to make it a success!
Understanding how light interacts with matter at the nanometre scale is a fundamental issue in optoelectronics and nanophotonics. It is known that the optical properties of nanoparticles are entirely dependent of excitations known as "surface plasmons". See how we managed to maps plasmons physical properties at the nanometer scale...
