Emagister Eventos

Organizado por ICTS Centro Nacional Microscopía Electrónica

III International Workshop ELECMI

  • Fechas:

    Del 03/06/19 al 04/06/19

  • Lugar:

    Salón de Actos (Edificio Biblioteca), Facultad Ciencias Químicas Universidad Complutense de Madrid, Madrid, España (mapa)

Web del evento

Descripción ↑ subir

3rd ELECMI International Workshop

June, 3rd - 4th 2019

NATIONAL CENTER FOR ELECTRON MICROSCOPY-UCM

FACULTAD DE QUÍMICAS. UNIVERSIDAD COMPLUTENSE. 28040-MADRID. SPAIN

Organized by ICTS ELECMI


ICTS (acronym from Instalación Científico Técnica Singular) are facilities, resources, and services, for the development of high quality cutting-edge research and, to promote transfer, exchange and preservation of knowledge, technology and innovation. They are unique or exceptional in their scientific areas and of strategic importance that justifies their availability to all actors in the field of R&D"> The aim of the 3rd ELECMI International Workshop is to be an excellence international forum for the promotion of Advanced Microscopies, strengthening of already existing collaborations and laying the foundations for new ones. To achieve this objective representative scientists working at the forefront of materials characterization will present their latest results and reflections on the future of Electron Microscopy and associated techniques. The venue for the 3rd ELECMI International Workshop is the National Center for Electron Microscopy (CNME) in the UCM.

Attendance to this workshop is free of charge, but registration is mandatory to help organizers with the logistics.


 

Lugar ↑ subir

Programa ↑ subir

June, 3rd

SCIENTIFIC PROGRAM

10:00-10:30

Coffee ">

 

10:30-11:15

Welcome Address

Secretaria General UCM (Prof. Araceli Manjón) – Subdirector General de ICTS MINCIU (Dr. José I. Doncel Morales) Director ICTS-CNME (Prof. J. M. González Calbet) General Manager Izasa Scientific, A Werfen Company (Dr. Carlos Arribas) Coordinadora ELECMI (Dr. Pilar Cea Mingueza)

11:15-12:00
Plenary Talk

Prof. Osamu Terasaki
ShanghaiTech University, Shanghai, China

EM structural study of fine structure of zeolites”

Chairperson

Prof. J. M. González Calbet

12:00-12:30
Invited Talk

Dr. Luisa Ruiz
Dpto. Q. Inorgánica, UCM, Spain

“Atomic resolved study of manganese mixed oxides”

Chairperson

Prof. Ricardo Ibarra

12:30-13:00
Invited Talk

Dr. J. C. Hernández-Garrido
University of Cádiz, Spain

“Electron Microscopy for Nanocatalysts: New Dimensions in Catalysis”

13:00-13:30

Invited Talk

Prof. Francesca Peiró

ELECMI

University of Barcelona, Spain

“TEM techniques applied to advanced materials for fuel cells: from electron diffraction to analytical tomography”

13:30-15:00

Lunch

 

15:00-15:45
Plenary Talk

Dr. Marta Rossell
EMPA, Switzerland

“Ferroelectric Domain Imaging in Multiferroic Oxide Thin Films”

Chairperson

Dr. Pilar Cea

15:45-16:15
Invited Talk

Prof. María Varela
Dpto. Física Materiales UCM, Spain

“Live, high resolution STEM-EELS mapping of atomistic processes in magnetic nanosystems”

16:15-16:45
Invited Talk

Dr. Raúl Arenal
ELECMI-LMA, University of Zaragoza, Spain

"From the Atomic Structure to the Optoelectronic Properties Studies of Carbon and Related Nanostructures via Transmission Electron Microscopy"

16:45-17:15

Break Time

 

17:15-17:45
Invited Talk

Prof. José Juan Calvino

ELECMI
University of Cádiz, Spain

“Combining Data Analysis Strategies and Multidetector Capabilities to Exploit Aberration-Corrected Electron Microscopy”

Chairperson

Prof. Francesca Peiró

17:45-18:15
Invited Talk

Dr. Miguel Tinoco
ELECMI-CNME, UCM, Spain

“Strain effects and edge structures in MoS2

     

20.30

Dinner

 
     

 

 

 

June, 4th

Abstract

9:15-10:00

Plenary Talk

Prof. Juan Carlos Idrobo Tapia

Oak Ridge National Laboratory, USA

“A Brief Look into Electron Microscopy in the Quantum Information Era”

Chairperson

Prof. María Varela

10:00-10:30

Invited Talk

Dr. Mariona Cabero

IMDEA ">

“O vacancy engineering in LaCoO3 and La1−xSrxCoO3−δ thin film”

10:30-11:00

Invited Talk

Dr. Paolo Longo

Gatan Inc., USA

“New advances in EELS detectors and acquisition strategies”

11:00-11:30

Coffee

 

11:30-12:00

Invited Talk

Dr. Sonia Estradé

University of Barcelona, Barcelona Spain

“EELS determination of the low temperature phase of magnetite nanocubes”

Chairperson

Prof. Jacobo Santamaría

12:00-12:30

Invited Talk

Dr. Jaume Gázquez

ICMAB, CSIC, Spain

“Linear dichroism in a scanning transmission electron microscope”

12:30-13:00

Invited Talk

Dr. Almudena Torres
Dpto. Q. Inorgánica, UCM, Spain

“Applications of advanced STEM techniques in the study of functional materials based on transition metals”

13:00-13:30

Invited Talk

Dr. Hugo Pérez Garza

DENS Solutions

“MEMS-based in-situ Transmission Electron Microscopy for Advanced Studies”

14:00-15:30

Lunch

 

15:30-16:15

Plenary Talk

Dr. Takeo Sasaki

JEOL Ltd. UK

“Feasibility of in-situ gas injection observation using latest Cs-corrected STEM/TEM”

Chairperson

Dr. Carlos Arribas

16:15-16:45

Invited Talk

Dr. Gabriel Sánchez Santolino
ICMM, CSIC, Spain

“Atomic Resolution Electric Field Imaging by Differential Phase Contrast Scanning Transmission Electron Microscopy”

16:45-17:15

 

Break Time

 

17:15-17:45

Invited Talk 

Dr. F. Javier García
ELECMI-CNME, UCM, Spain

“Old duties on a new light: crystal-chemistry in the Cs corrected transmission electron microscope”

Chairperson

Prof. J. M. González Calbet

17:45-18:15

Invited Talk

Dr. César Magén Domínguez

ELECMI

Instituto de Ciencia de Materiales de Aragón. CSIC, Spain

“Probing ferromagnetism of 3D FEBID nanostructures by off-axis electron holography

18:15-19:00

Plenary Talk

Prof. José López Carrascosa

Research Professor

Centro Nacional de Biotecnología, CSIC

“The resolution revolution in Cryo-TEM for Life Sciences

 

 

3
Jun 2019
  • 10:00 - 10:30
    Coffee & Registration
  • 10:30 - 11:15
    Welcome Address

    Secretaria General UCM (Prof. Araceli Manjón) – Subdirector General de ICTS MINCIU (Dr. José I. Doncel Morales)  Director ICTS-CNME (Prof. J. M. González Calbet) General Manager Izasa Scientific, A Werfen Company (Dr. Carlos Arribas) Coordinadora ELECMI (Dr. Pilar Cea Mingueza)

  • 11:15 - 12:00
    Plenary Talk. Prof. Osamu Terasaki

    JW Menter observed, for the first time, lattice fringes of natural mineral FAU, which has large lattice spacing enough to be observed by EM with the resolution limit (ca. 10 Å) at that time.  Later zeolites were recognised as one of the most electron-beam sensitive materials. After the Menter’s pioneering work, EM was mostly applied to detect the presence of small amounts of impurities and to study zeolite fine structures mostly through ED patterns. In early seventies, JV Sanders and his colleague developed from a lattice image to the structure image for the study of the fine structure of zeolites. JM Thomas and his group in Cambridge further developed various techniques useful for HRTEM observation of zeolites, such as dehydration, dealumination (to decrease Al/Si ratio of framework) and ion-exchange with heavy ions. At the time, I learned from José M. González Calbet at Cambridge how to tackle e-beam sensitive zeolites for HRTEM observation. After that I have spent so long time to study fine structure of zeolites by determining arrangement of pores with different sizes through EM (HRTEM images & ED patterns). It was very time consuming, labour demanding and low-productive periods.  This was because that the sensitivity of e-beam detectors (fluorescent screen and photographic films) was too low to image e-beam sensitive nanoporous crystals and EM spatial resolution was also limited.  However, recent enormous technical developments in both detector and lenses with Cs correctors make it possible to image all atoms including Oxygen of zeolite frameworks, so I will talk historical aspects, present some of recent S/TEM works and discuss future dreams.

  • 12:00 - 12:30
    Dr. Luisa Ruiz: "Atomic resolved study of manganese mixed oxides"

    Understanding the intriguing chemical and physical properties of functional oxides is a key factor for their performance. Manganese mixed oxides, belonging to different structural types, are on the basis of many technological applications in the electronic, spintronic and catalytic fields, among others. Although a great variety of phenomena have been described in this vast family of compounds, all of them share characteristics such as the existence of several competing states as consequence of different kinds of interactions: spin, charge, lattices and orbital. All of them can take place from the atomic to longer length scales passing through the nanoscale and represent a goal of primary interest for the electron microscopy.  In this context, the aim of this talk is to show some results devoted to the characterization at atomic level of several manganese oxides of different composition, structural-type, particle size and dimensionality in which Mn3+ and Mn4+ oxidation states as well as local ordered disordered phenomena coexist.

  • 12:30 - 13:00
    Dr. J. C. Hernández-Garrido: "Electron microscopy of catalytic materials: exploring new capabilities for an advanced characterization"

    The beginning of the 21st century has brought a real outbreak in the form of using nano-materials in heterogeneous catalysis. Due to a much higher specific surface area than macro materials, the effectiveness of nano-catalysis is much higher. In this sense, developments in electron microscopy techniques are providing more realistic views of catalysts, allowing optimization of their structure to improve their performance. The potential of these techniques will be illustrated with different examples related to the following topics related to nanocatalyst characterization: 1) Structured catalysts, 2) Morphologically -controlled catalysts and 3) atomically dispersed and clusters catalysts.

    In these examples, the proper combination of Focused Ion Beam and STEM techniques, the 3D reconstruction by tomography techniques and an advanced image processing and analysis were used to encourages exploiting from these techniques into the catalyst characterization from the different dimensions scale.

  • 13:00 - 13:30
    Prof. Francesca Peiró: "TEM techniques applied to advanced materials for fuel cells: from electron diffraction to analytical tomography"

    Fuel cells solid state devices are at the core of a new paradigm for energy production based on the hydrogen vector. Tuning the oxygen mass transport or proton conductivity through the solid electrolyte is one of the key aspects to control the performance of the fuel cells, and therefore, the research towards new materials exhibiting convenient electronic-ionic conductivity properties has centered the interest for many years. Electron microscopy tools and related spectroscopies are essential to reveal the structural and local compositional changes that ultimately define the performance of the material. We will review some examples based on rare earth fluorite type niobates (RE3NbO7), perovskite manganites with general formula RE1−xBxMnO3±δ (where RE stands for a trivalent rare-earth element and B for a divalent alkaline ion) and high-surface-area mesoporous CeO2 doped with Gd and Pr.

  • 13:30 - 15:00
    Lunch
  • 15:00 - 15:45
    Plenary Talk. Dr. Marta Rossell: "Ferroelectric domain imaging in multiferroic oxide thin films"

    Multiferroic materials that exhibit simultaneous -and strongly coupled- magnetic and ferroelectric order above room temperature are ideal candidates for applications in next-generation memory devices utilizing low consuming electric fields to control magnetic order. However, due to competing requirements for displacive ferroelectricity and magnetism, only a handful of single-phase materials displaying multiferroic properties above room temperature are known. Most multiferroics remain elusive either because they exhibit antiferromagnetic or weak ferromagnetic alignments, small spontaneous polarization, week coupling between the order parameters, or because their properties only emerge at extremely low temperatures. Therefore, much effort is devoted to search new single-phase multiferroic materials that exhibit high ordering temperatures.

    In this contribution, we will show recent advances on the characterization of ferroelectric domain structures in multiferroic oxides. In particular, we will present results on the domain structures of a few selected systems obtained by means of aberration-corrected scanning transmission electron microscopy (STEM), differential phase contrast STEM, and in-situ heating/electrical biasing STEM.

  • 15:45 - 16:15
    Prof. María Varela: "Live, high resolution STEM-EELS mapping of atomistic processes in magnetic nanosystems"

    High resolution visualization of atomistic processes across interfaces under relevant external stimuli is a must in order to understand the atomic origin of macroscopic functionalities found in magnetic nanosystems. After the success of aberration correction in the electron microscope, novel imaging, diffraction and spectroscopic techniques have been rapidly developed and the era of multidimensional electron microscopy is emerging. Furthermore, external stimuli are readily available such as the application of electric bias, varying temperature or magnetic fields in order to image processes responsible for diverse macroscopic functionalities with atomic resolution, in real space. Here, we will discuss a few systems where these techniques hold the key to understanding macroscopic functionalities in nanometric magnetic systems. Examples will include the live visualization of electron beam induced reduction of Mn oxide/ Fe oxide core-shell nanostructures with unusual exchange bias properties, chemical segregation in Bi-rich Cu-Bi nanowires exhibiting giant spin-Hall effect or the magnetic field and temperature induced chemical inhomogeneity found in Ni-Fe nanoparticles coated with graphene, which can be associated with a hundred-fold enhancement of capacitance. Collaborators & Acknowledgements: M. Roldán (Arizona State University) & J. Nogués (ICN2 Barcelona, ICREA & CSIC), S. Ruiz & L. Pérez (U. Complutense of Madrid, Spain), G. Abellán & E. Coronado (U. of Valencia). Financial support from Spanish MAT2015-066888-C3-3-R (MINECO/FEDER) and ERC Proof-of-Concept POLAR-EM is acknowledged.

  • 16:15 - 16:45
    Dr. Raúl Arenal: "From the Atomic Structure to the Optoelectronic Properties Studies of Carbon and Related Nanostructures via Transmission Electron Microscopy"

    The last decades, the scientific community has developed a broadening interest in different 1D and 2D Carbon and related nanostructures; due to their attractive mechanical, thermal and electronic properties. For a better understanding these materials, the study of their structure and properties, at the local (atomic) scale, is highly required. The recent advances in TEM bring access to electron probes of one angstrom within energy resolutions of few meV, working at low acceleration voltages (60-80 kV), offer the best possibilities for achieving these goals. In this contribution, we will present our recent works concerning the study of the atomic structure & configuration of 1D and 2D atomically thin materials (in pristine and hybrid/functionalized forms) as well as the optoelectronic properties studies carried out via EELS measurements.

    This work was supported by the Spanish MINECO (MAT2016-70776-P), the EU H2020 program Marie Sklodowska-Curie “EnEx” (Grant Agreement 642742), the EU H2020 & APCIN-MICINN Spain (JTC-2017 Flag-ERA GATES project), the EU H2020 program “ESTEEM3” (Grant Agreement ) and the EU H2020 program “Graphene Flagship” (Grant Agreement 785219) .

  • 16:45 - 17:15
    Break Time
  • 17:15 - 17:45
    Prof. José Juan Calvino: "Combining Data Analysis Strategies and Multidetector Capabilities to Exploit Aberration-Corrected Electron Microscopy”

    Modern Aberration Corrected microscopes provide not only information at the highest spatial and energy resolution but, at the same time, the opportunity to record simultaneously a variety of signals. By properly combining some of them with appropriate data analysis tools, structural and compositional details can be retrieved which in most cases fall out of reach for the individual signals.

    The potential of this approach will be illustrated with different examples related to the following topics related to nanocatalyst characterization:

    1) spatial distribution of nanosized noble metal particles supported on heavy oxides;

     2) strain in MgO supported mixed CeOx-TbOx ultrathin layers;

    3) determination of the oxygen content in complex mixed oxide nanorods with hollandite structure and 4) quantitative characterization of atomically dispersed metal atoms and subnanometer clusters.

    In these examples, image processing by undecimated wavelet transforms; image analysis by template matching and peak pair correlation or clustering techniques; and 3D reconstructions by advanced, compressive sensing based, methods were used to analyse the information recorded from different detectors while working in the STEM mode. Such information revealed structural features which allow a better understanding of their catalytic performance.

  • 17:45 - 18:15
    Dr. Miguel Tinoco: "Strain effects and edge structures in MoS2"

    It is widely acknoledged that MoS2 remarkable properties strongly depend on its dimensionality. However, its has recently been proven that macroscopic strain, and the edges of the 2D structures, also play an important role in determining these properties. In particular, it has been predicted that MoS2 electronic properties can be tailored by creating strain on the MoS2 layers or by selecting the type of edge sites exposed. In this presentation we will focus on the effects of microscopic strain on the excitonic response of MoS2, and the electronic character of the different edges of MoS2 by using focus ion beam and advanced transmission electon microscopy. Our results pave the way towards the design of complex nanostructures based on MoS2 for applications in fields such as electronics, optoelectronics, photovoltaics, and photocatalysts.

  • 20:30 - 23:59
    Dinner
4
Jun 2019
  • 09:15 - 10:00
    Plenary Talk. Prof. Juan Carlos Idrobo Tapia: "A brief look into electron microscopy in the quantum information era"

    Scanning and transmission electron microscopes (S/TEM) are now ubiquitous in materials and biological sciences laboratories.  They have radically enhanced our understanding of organic and inorganic matter with the successful development of aberration correctors [1,2], detectors with film-equivalent dynamical range [3], and more recently, with monochromators capable of achieving sub-10 meV energy resolution spectroscopy [4]. 

    Here, I will present several examples demonstrating how we have exploited these capabilities and solved the pertinent experimental challenges to probe materials behavior at the nanometer and atomic scales.  Specifically, I will show how by utilizing the phase of the electron probe one can reveal the magnetic order of complex-oxide materials at the atomic level [5].  I will also explain how the new generation of monochromators, combined with aberration-corrected STEM, can be used (i) as a primary thermometer (without requiring any previous knowledge of the sample) [6]; (ii) to study minute volumes of liquid water [7]; (iii) to detect site-specific isotopic labels in amino acids at the nanometer scale [8].  Additionally, I will show how one can detect the electric field of individual atomic columns of heavy and light elements, at the sub-Angstrom scale, by using an ultra-low noise SCMOS detector in the diffraction plane [9].

    Lastly, I will discuss potentially relevant new challenges that electron microscopy will need to resolve as it enters the forthcoming quantum information era.  Will it be possible to map orbitals and spins with atomic resolution and with single atom sensitivity? Can we detect a superconducting transition? Can we spectroscopically measure cryogenic temperatures with sub Kelvin precision?  Can we measure the specific heat and thermal conductivity of materials? Can we detect minute concentrations of isotopic elements and perform radiocarbon dating at the nanoscale?  These questions will be addressed and further elaborated during the presentation [10].

    References:

    [1] J. Zach and M. Haider, Optik 99 (1995), p. 112.

    [2] O. L. Krivanek, et al, Institute of Physics Conference Series 153 (1997), p. 35.

    [3] A. R. Faruqi, R. Henderson, Curr. Opin. Struc. Biol. 17 (2007), p. 549.

    [4] O. L. Krivanek, et al, Phil. Trans. R. Soc. A 367 (2009), p. 3683.

    [5] J. C. Idrobo, et al, Adv. Struc. Chem. Img. 2 (2016), p. 5.

    [6] J. C. Idrobo, et al, Phys. Rev. Lett. 120 (2016), p. 095901.

    [7] J. R. Jokisaari, et al, Adv. Mater. 30 (2018), p. 1802702.

    [8] J. A. Hachtel, et al, Science 363 (2019), p. 525.

    [9] J. A. Hachtel, et al, Adv. Struc. Chem. Img 4 (2018), p. 10.

    [10] This research was supported by the Center for Nanophase Materials Sciences, which is a Department of Energy Office of Science User Facility, and instrumentation within ORNL's Materials Characterization Core provided by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.

     

  • 10:00 - 10:30
    Dr. Mariona Cabero: "O vacancy engineering in LaCoO3 and La1−xSrxCoO3−δ thin film"

    The ability to control spin states via O vacancy engineering offers new avenues towards the tunning of magnetic properties in complex oxides. In particular, LaCoO3 (LCO) epitaxial films under strain have shown a ferromagnetic behaviour at low temperaturas due to the combination of epitaxial strain and the presence of arrays of O vacancies. Likewise, La1−xSrxCoO3−δ (LSCO) thin films grows with high density of O vacancies which promote unexpected spin state superlattices. We Will focus on atomic strain determined by transmission electron microscopy on ultrathin LCO and LSCO layers and we demonstrate that strain-engineered vacancy ordering in these systems generates changes in the magnetic anisotropy.

  • 10:30 - 11:00
    Dr. Paolo Longo: "New advances in EELS detectors and acquisition strategies"

    The acquisition of high-quality EELS data in the transmission electron microscope (TEM) presents many challenges not experienced by most TEM acquisitions. The central challenges lie around dose efficiency, reduced noise and point spread function and dynamic range. For EELS, the range of intensities can often span by several orders of magnitude making recording problematic especially when the low-loss portion of the spectrum with the zero-loss peak is present. To address these issues 10 years ago we developed the GIF Quantum that included a new design CCD based detector capable to achieve very high spectra rate with little overhead. The GIF Quantum was a major step forward from the previous technology in the GIF Tridiem. Fast acquisition that can take advantage of the increased electron dose in Cs probe corrected microscopes was then possible and techniques such as atomic EELS that requires high spectral rate became routine. However, such high spectral rate in the Quantum came with an increased instrumental noise due to binning which is a must to achieve speed and sensitivity. This higher instrumental noise has been in the main bottle neck for chemical and traces analysis where quality is very important. To overcome the problem of high instrumental noise we developed EELS data acquisition in counting mode using the K2 camera. The K2 is a direct detection camera capable of directly counting each individual electron event at a speed of 400 fps. The K2 has been a huge success for EELS applications because of the reduced noise and point spread function (PSF). The improved PSF allows spectra to be acquired over larger energy ranges while maintaining sharp features and greatly reduced spectral tails. The ability of counting nearly eliminates all the instrumental sources of noise. This effectively leaves the shot noise as the limiting source of noise. The main limitations of the K2 for EELS data acquisition are the spectral rate which is limited to 400 fps and the dynamic range. Given the low amount of signal typical of core-loss analysis, the limited dynamic range of the K2 has not been a limitation at all. Such limitations typical of the K2 have been overcome with the introduction of the K3 with a 4x improvement in dynamic range and nearly 10x in spectral rate. The K3 camera is capable of counting electrons at a speed of 3000 spectra per second. In addition to the developments we have made in the field of counting EELS detectors with the K2 first and the K3 now, we just released the GIF Continuum. The GIF Continuum like the GIF Quantum employs indirect camera technology where incident electrons are converted to photons a coupled through fiber optics to a light sensitive camera. Unlike the GIF Quantum, the GIF Continuum is equipped with a low noise CMOS detector capable of delivering 8000 spectra per second at nearly 100% duty cycle and without the need of binning. That coupled with a more sensitive and lower noise scintillator/fiber optics camera stack allows the acquisition of high quality and reduced noise EELS spectra at high spectral rate. Many more technological advancements have been introduced in the GIF Continuum and the implications for EELS data analysis will be discussed.

  • 11:00 - 11:30
    Coffee
  • 11:30 - 12:00
    Dr. Sonia Estradé: "EELS determination of the low temperature phase of magnetite nanocubes"

    The exact nature of the metal-insulator transition experienced by magnetite at about 125 K is a matter of ongoing interest and debate in condensed matter physics. Here, we use the high spatial and energy resolution offered by aberration corrected transmission electron microscopy techniques to study single 24 nm magnetite particles by in situ cooling. A transition from the room temperature cubic inverse spinel phase to a low temperature, defect free, monoclinic phase is found by high resolution transmission electron microscopy (HRTEM). However, the fast Fourier transform of the HRTEM images does not allow us to discriminate between the three different crystal structures proposed for the low temperature phase.  However, by comparing the experimental EEL spectra with density functional theory calculations, it is possible to determine the actual space group at low temperature.

  • 12:00 - 12:30
    Dr. Jaume Gázquez: "Linear dichroism in a scanning transmission electron microscope"

    The orbital polarization is a measure of the distinct orbital occupancy, and the common tools to determine it is X-ray linear dichroism (XLD), being the difference between absorption of light polarized parallel and polarized perpendicular to an orientation axis. However, these measurements are macroscopic while changes occur at particular atomic sites. I will show how to probe the linear dichroic signals arising at interfaces in thin film complex oxides with atomic resolution using electron energy-loss spectroscopy (EELS) in an aberration-corrected scanning transmission electron microscope (STEM). I will compare our measurements with XLD obtained from the same samples. We have used mixed-valence manganite (La0.7Sr0.3MnO3) thin films with different capping layers as a testbed to explore the interaction between dissimilar oxides at interfaces.

  • 12:30 - 13:00
    Dr. Almudena Torres: "Applications of advanced STEM techniques in the study of functional materials based on transition metals"

    Correlating structure and function is fundamental for the design of functional materials based on transition metals. Specifically, the atomic rearrangement within a particle and the various oxidation states and magnetic behaviors of transition metals has a direct effect on its properties. Our approach is using atomic resolution STEM and associated spectroscopic techniques (EELS and EDS) to unravel the atomic structure of the particles as well as the local oxidation state of the transition metals, therefore allowing the understanding of the origin of the functionality of the structures. Here, the study of compounds based on transition metals with magnetic, catalytic, electrochemical and luminescent properties will be described. Specifically, we will present the capabilities of aberration-corrected microscopy to provide valuable structural and analytical information to be correlated with their functional properties.

  • 13:00 - 13:30
    Dr. Hugo Pérez Garza: "MEMS-based in-situ Transmission Electron Microscopy for Advanced Studies"

    Investigating materials at the nanoscale has become vital in order to address the challenges our world is facing in a wide range of topics, both from the industrial and fundamental points of view. In order to keep advancing, microscopy analysis has been providing the means to study and characterize the nanostructural features of different materials (both biological and synthetic), as well as composites and products. In particular, Transmission Electron Microscopy (TEM) is a powerful tool that helps revealing detailed morphological information that can be related to sub-standard performance or unwanted structural or visible properties. In conventional TEM, the user deposits a sample on a copper grid. However, conventional TEM works under static conditions, at room temperature and in vacuum. And although this microscopy technique could enable atomic resolution, it would be ideal to understand and visualize in real-time the dynamic events of the sample as a consequence of a given stimulus. Having this capability would be necessary to determine how to optimize the different materials and processes. Here, I present the development of Micro Electro-Mechanical Systems (MEMS) as the ultimate sample carrier to enable in-situ TEM studies. Such MEMS devices, referred to as Nano-Chips, replace the traditional copper grid and are equipped with different nano-sensors and/or nano-actuators in order to bring different stimuli to the sample. Therefore, the Nano-Chip acts as a multi-functional sample carrier and nano-sized laboratory for simultaneous types of stimuli (e.g. heat, pressure, liquid, bias, etc). At DENSsolutions, we have developed four different product lines to address all challenges and provide researches with the ultimate way to study and understand their samples. Different scientific applications for each of the developed systems will be discussed. For example, we are proud to contribute to solar panels and batteries that last longer with more storage capacity. Similarly, these systems can enable scientists to develop new nano-medicines for better health and new semiconductors for smarter electronic devices. We believe the Nano-Chips hold the key to revolutionize research, since they will enable scientists to understand the exact relationship that there is between structure-property-process.

  • 14:00 - 15:30
    Lunch
  • 15:30 - 16:15
    Plenary Talk. Dr. Takeo Sasaki: "“Feasibility of in-situ gas injection observation using latest Cs-corrected STEM/TEM"

    Cs-corrected (scanning) transmission electron microscopes (Cs-corrected STEM/TEM) have been important with materials scientists for couple of decades due to tremendous benefits such as enhancement of resolution and analytical efficiency. Taking advantage of these enhanced capability for imaging and analyzing materials, further challenges have been addressed to observe chemical reactions of nano-particles under gas atmosphere. SiN membrane-type gas cell holders have been utilized for in-situ investigations of such reactions because the column of the microscope is not exposed by reaction gases and maintained in a good vacuum condition. Introduced gases flow through inside the membrane cell to stimulate chemical reaction of the specimen.

    However there is a risk that intensely focused probe with a large probe current could drill the SiN membrane and reaction gases could leak out of the gas cell to the column, giving rise to vacuum degradation of TEM column. The vacuum change due to the gas leakage from the in-situ gas holder has not yet been investigated from the gun vacuum safety point of view in JEOL microscope and needs to be calibrated. The purpose of this study is to understand a response of the vacuum change in gas leakage in 300 kV corrected microscope and test a feasibility of in-situ gas injection experiment in TEM.

    In this talk, we demonstrate a trial result on in-situ gas redox reaction observation as a part of latest application study as well as basic ideas and key points to understand principles and actual operations of Cs-corrected microscopes from beginner-users point of view.

  • 16:15 - 16:45
    Dr. Gabriel Sánchez Santolino: "Atomic Resolution Electric Field Imaging by Differential Phase Contrast Scanning Transmission Electron Microscopy"

    The functional properties of materials and devices are critically determined by the presence of electric field structures inside them, especially at interface regions. Differential phase contrast (DPC) imaging in the electron microscope enables the study of such localized fields in materials. When electric fields are present inside the sample, the incident electron beam is deflected, producing a shift of the intensity on the detector plane proportional to the field strength. Advances in segmented and pixelated detectors combined with state of the art aberration correction technologies have enabled the possibility of precisely detecting these shifts and thus imaging the electric fields in materials with atomic resolution [1]. Recent studies have shown the direct imaging of the atomic electric field [2, 3], the chemical bonding states for single atoms [4] and the distribution of the internal atomic charge densities, including both the positively charged nucleus and the surrounding negative electrons [5]. In this talk, current status and prospects for atomic resolution DPC STEM imaging will be discussed.

    References:

    [1] N. Shibata et al., Nature Physics, 8, 6115 (2012)

    [2] K. Müller et al., Nature. Communications, 5, 5653 (2014)

    [3] N. Shibata et al., Nature Communications, 8, 15631 (2017)

    [4] R. Ishikawa et al., Nature Communications, 9, 3878 (2018)

    [5] G. Sánchez-Santolino et al., ACS Nano, 12, 8875 (2018)

  • 16:45 - 17:15
    Break Time
  • 17:15 - 17:45
    Dr. F. Javier García: "Old duties on a new light: crystal-chemistry in the Cs corrected transmission electron microscope"

    The task for a crystal-chemist is the characterization of solid state compounds. This should be done according to a parent or aristotype structure type, which it is always selected to crystallize in the highest possible symmetric space group. However, solid state compounds are prone to be slightly different from the parent structure type through structural distortions. These are ubiquitous in solid state compounds and they affect the symmetry of the structure by taking it down to an space group which it is normally in a group-subgroup relation with that of the parent structure.   

    The most noticeable effect of these distortions is the presence of extra Bragg reflections and/or diffuse diffracted intensity in the reciprocal lattice. Here is where electron microscopy plays a key function due to the strong interaction of electrons with matter along with the ability to map the associated reciprocal lattice in different directions. Up to this point not much is added by using the Cs corrected microscopes. Nevertheless, the achievement of resolutions below 0.1 nm is with no doubt of much help. In this scale of spatial resolution, we are able to tackle the mapping of structural distortions, what constitute the subject matter of this presentation. The characterization of a few displacively and compositionally distorted structures is going to be presented and discussed.

  • 17:45 - 18:15
    Dr. César Magén Domínguez: "Probing ferromagnetism of 3D FEBID nanostructures by off-axis electron holography"

    Three dimensional (3D) magnetic nanostructures attract particularly keen interest because of their possibilities to be implemented in future spintronic devices such as high-density magnetic memories, nano-sensors or logic devices [1]. However, the synthesis and detailed characterization of these systems are far more complex than in 2D architectures. One of the synthetic techniques explored recently is Focused Electron Beam Induced Deposition (FEBID), a unique one-step nanolithography technique which has demonstrated great versatility, and has successfully been used to grow of 3D ferromagnetic nanostructures of cobalt and iron [1-2]. However, the magnetic properties of as-grown 3D FEBID ferromagnets based on Co and Fe degrades as the lateral dimensions are reduced below 100 nm, and different strategies have to be followed to optimize metallic content [2].

    This lecture summarizes the investigations carried out to design synthetic methods to grow novel architectures of 3D FEBID ferromagnetic nanowires [3-5], and the detailed characterization of their physical, chemical and magnetic properties by advanced transmission electron microscopy techniques [2-5]. In this task, the application of off-axis Electron Holography to determine quantitatively the local magnetic properties of the nano-objects has been key to optimize their properties.

    [1] Fernández-Pacheco, A. et. al., Sci. Rep. 3, 1492 (2013).

    [2] Pablo-Navarro, J. et. al., J. Phys. D 50, 18LT01 (2017).

    [3] Pablo-Navarro, J. et. al., Nanotechnology 27, 285302 (2016).

    [4] Pablo-Navarro, J. et. al., ACS Appl. Nano Mater. 1, 38 (2018).

    [5] Pablo-Navarro, J. et. al., manuscript in preparation.

  • 18:15 - 19:00
    Prof. José López Carrascosa: "The resolution revolution in Cryo-TEM for Life Sciences"

    Transmission electron microscopy (TEM) produces two-dimensional projection images of specimens provided they can sustain vacuum environment and electron interaction. When dealing with biological materials, these two factors demand the use of elaborated sample preparation methods to retrieve structural information by TEM. In the last years, three main factors have emerged which have improved TEM applications in Biomedicine: the use of low temperature (cryo-EM) to acquire data from fast frozen samples, the incorporation of direct electron detectors, and the implementation of robust and sophisticated image processing methods to retrieve high resolution information in three dimensions. These improvements have resulted in a technical revolution which has positioned cryo-TEM as a method of choice for Structural Biology.

    Application of Cryo-TEM for the structural analysis of macromolecular complexes has several advantages: it requires small amounts of sample, it does not demand full purification (as it allows in silico selection of specimens), and provides the way to address the study of different conformational states of a particular macromolecular complex. Depending on the sample, present technology allows for a wide range of complex sizes to be solved at atomic resolution, from several MDa to less than 0.1 MDa, being this lower size where the attainable resolution is more compromised.

    The other main area of cryo-TEM development is Cellular Structural Biology, where there is a demand for detailed structural and functional descriptions of the different cellular components which must be correlated with a topological 3D map of these components at the cellular level. Here, the main problem is imposed by the limited penetration of electrons in biomaterials (around 500 nm). In this case, production of sections is a requirement that has been traditionally fulfilled by different approaches (plastic embedding, cryosectioning). The recent incorporation of sample milling by ion beams to produce frozen lamellas has allowed to apply cryo-TEM tomographic methods to retrieve three-dimensional reconstructions of cellular environments up to 1-3 nm resolution.

Ponentes ↑ subir