Advanced Characterization of Materials: Relevance and Challenges.
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Transcript of Advanced Characterization of Materials: Relevance and Challenges.
Advanced Characterization of Materials Relevance and Challenges
Aldo Craievich
Instituto de Física
Universidade de São Paulo
São Paulo –SP
XV Meeting of the Brazilian MRS, Campinas, 5 to 9 September 2016
Institute of PhysicsUniversity of Sao Paulo
Advanced Characterization of Materials.Relevance and Challenges
Outline
I - Structural characterization of materials and Crystallography. Relevance.
II - A short historical view of Crystallography, X-ray diffraction and diffuse scattering.
III - The use of synchrotron radiation sources. First Brazilian second-generation synchrotron
IV - New advanced techniques. Fourth-generation synchrotrons.
V - New advanced techniques. Fifth generation light sources (X-ray free electron lasers).
VI - New advanced facilities for investigations of materials in Brazil.
VII - Challenges, future trend and final remarks.
I - Structural characterization of materials and Crystallography.
Relevance
Crystallography. Structure and properties of materials
PurposeUnderstanding the properties of materials and mechanisms of transformation based on experimental measurements by using X-ray scattering techniques and theoretical foundations:
- Determinations of atomic and electronic structures at different length and time scales,
- Applications of theories associated to material properties (based on quantum mechanics, dislocation theory, statistical mechanics, thermodynamics…).
ConsequenceHelping developments of new materials with desired properties
Chemical and physical properties
Theory of solid-statephysics and chemistry
Atomic and electronicstructures at different spatial
and time resolution
Understanding the properties of materials
Relevant structures and spatial resolution
Atomic Nanometric
Micrometric Macroscopic
An example of structural characterization ad understanding of a physical propertySemiconductor quantum dots embedded in a transparent glass
Optical properties
A
ADoped-glass
melting
Quenching
Isothermal growth of semiconductor NPs
S1
S2
S3 S1 S2 S3
Temperature
Time
Roomtemperature
Visible
(white) light
Example of structural characterization ad understanding of a physical propertySemiconductor quantum dots embedded in a transparent glass
A
A
EgapStructural transformation
(Time dependent structure)
From basic theory: Efros and Efros equationEgap=(Egap)macro - K/R2 Property Nanostructure Electronic structure
Classical X-ray diffraction and materials structure
▪ The most frequently used experimental procedure for studying the structure of materials is X-ray diffraction. Analyses of single-crystal X-ray diffraction patterns reveal the geometry of unit cells and the coordinates of the atoms inside them.
▪ The problem is that atomic structures of unit cells determined by applying this technique are time averages and spatial averages of many instantaneous and local structures, respectively.
▪ For this reason, the results derived from classical single-crystal X-ray diffraction patterns do not describe neither instantaneous configurations of moving atoms nor detailed local structures of point, linear, surface and volume defects.
▪ This restrains our understanding of the properties of materials that depend more on their instantaneous structure or local configurations of structural defects than on the features of their time or spatially averaged structures.
▪ However extremely important discoveries were achieved during the 100 years lasted from the first use of X-ray diffraction associated to the scientific field of Crystallography, which led to more than 40 Nobel prizes in Physics, Chemistry and Medicine.
II - A short historical view of 100 years of Crystallography, X-ray diffraction
and diffuse scattering
1914 – First unit cell structure determinations-
Bragg (father and son)
1939 – Hardenning of aluminum-copper alloys .
Guinier-Preston zones
~1950 – Structure of proteins. Perutz and Kendrew
1952 – Structure of DNA. Watson and Crick
1984 – Quasi-crystals – Schectmann
2005 – Graphene - Geim and Novoselov
One hundred years of Crystallography: X-ray diffraction and materials structure
1912 – First X-ray diffraction pattern - Laue
1914 – Coolidge X-ray tube
1980 – Dedicated synchrotron sources
2009 – X-ray lasers
2016 – 4th generation synchrotron sources
First structure determined by X-ray diffraction. Sodium chloride (NaCl)
FCC cubic Bravais lattice
Na+ at (0,0,0)
Cl- at (½,0,0)
W.L. Bragg, W.H. Bragg (1913) 2dsin q=l
Crystallographic structure and propertiesDiamond, graphite and graphene
X-ray diffraction pattern of DNA Structure model derived from XRD patterns
James Watson and Francis Crick (1953)
X-ray diffraction pattern of DNA Structure model derived from XRD patterns
L=34,0 A
d=3,1 A
2π/d
2π/L
Analysis of XRD patterns and determination of relevant structural parameters
I - Formation and growth of Guinier-Preston zones in AlCu alloys (One of the first nanostructured materials
developed by a bottom-up procedure).
First successful study of a nanostructured material: Aged Cu-doped Al alloys(A. Guinier, Nature 1938)
Aluminum alloysWilm (Germany) discovered in 1906 the effect of age-hardening of aluminum alloys.
Al alloy quenched in
water and aged at room
temperature
Quenching
Aging at room or at higher T
Solution treatment
Time
α
α
θ
Hardness
Aluminium 99,985%.
Aluminium and aged aluminum alloy
1920: Merica (EEUU) suggested that age-hardening is related to the presence of submicroscopic precipitates, without any experimental evidence for this statement.
Aluminium-4%copper
Time
Quenching
Aging
Solid solution
Al Composition (w.% Cu)
1906: Wilm (Germany) discovered the effect of age-hardening of aluminum alloys in 1906
Diffraction pattern of pure Al
Diffraction pattern of aged
Al Cu alloy
X-ray powder diffraction analysis of Al alloys
Why apparently age hardening of AlCu alloys is not
accompanied by a parallel structural transformation?
Why aged AlCu alloys harden?
Structure of age-hardened aluminum-copper alloysA.Guinier Nature, 24, 569-570 (1938)
Guinier (France)-Preston (UK) independently
discovered the presence of coherent Cu
nano-precipitates(Guinier-Preston zones)
dispersed in the matrix of Al-Cu alloys, which explained the “age-hardening” effect.
Guinier-Preston
(or GP) zones
André Guinier (1938)
This example illustrates …
(1) … the relevance of crystalline defects (for example GP zones) for understanding physical properties,…
(1) … the need of measuring the intensity of diffuse scattering (between Bragg peaks) in oder to properly characterize structure defects, and ...
(1) … the usefulness of time resolved characterization of materials structure in order to properly understanding variations in materials structures and associated properties.
]
Guinier-Preston (GP) zones
Al Cu
First successful study of a nanostructured material: Aged Cu-doped Al alloys (André Guinier, Nature, 1938)
III - The use of synchrotron radiation sources. First Brazilian second-generation synchrotron
The 1.37 GeV UVX Brazilian second generation synchrotron light source in operation at LNLS, Campinas (1997 – 2018)
Synchrotron X-ray, VUV, Vis and IR light sources based on electron storage rings1st generation (1960): Electron storage rings previously built for applications to high energy physics used in “parasitic” mode.
2nd generation (1980): Electron storage rings built for using synchrotron light mainly produced by bending magnets.
3rd generation (1990): Electron storage rings built for using synchrotron light mainly produced by undulators.
UVX electron storage ring
Electron energy: 1.37 GeVEmittance: 100 nm.rad
1981-1985 1985/86 Aug.-Dic. 1986
Jan.- Jul. 1987 Jul. 1987 – Out. 1995 Oct. 1995 - …
CBPF, Urca, Rio IFT, Rua Pamplona, São Paulo Campus UNICAMP, Campinas
Chácara Primavera Fazenda Santa Cândida Campus do GuaráCampinas Campinas Campinas
PRS LNRS LNLS
Mini-Curso “Espectroscopia de Raios X”realizado na sede de Faz. Santa CândidaOs participantes visitam a área onde foi
depois construida a fonte de luz síncrotron do LNLS (1990)
(1991) Starting the excavation of the tunnel for the 120 MeV injector linac
Main Building
First LNLS beam lines
Beam lines and emission spectrum
First visible fluorescence effects
produced by X-ray photons at LNLS (1997)
Selected articles published
(1975)
(1981)
Thoretical aspects: Use of Cahn theory for spinodal decomposition
(1981)
(1981)
Thoretical aspects: First application to glasses of the statistical theory of dynamical scaling
(1998)
(1997)
(1998)
(1999)
(2004)
(Phys Rev B 2008)
Theory: Validation for nanoscopic material of Lifschitz-Slyizv-Wagner theory for coarsening
Small (2012)
(PCCP 2010)
Needing characterizations of local structures of single nanocrystals
▪ The decreasing trend and suppression of undercooling in Bi nanocrystals with decreasing sizes were explained by a simple two-phase model consisting of a crystalline core surrounded by a disordered shell (Kellermann and Craievich Phys Rev, 2008).
▪ This conclusion is an indirect evidence of the heterogeneous nature of nanoparticles. In order to confirm the core-shell model of the local structure of single nanocrystals should be determined.
▪ Melting and freezing of central core and “shell” structure - close to the external surface of nanocrystals - do not simultaneously occur. Again this heterogeneous melting process requires a local structural characterization of individual nanoparticles.
Core-shell
model
Melting
Phase diagrams of nanocrystals were determined for samples composed of nanocrystals with a rather wide size and shape distribution (Abdala et al, PhysChem-ChemPhys, 2010). Structural studies of individual crystals with different known sizes and shapes would provide a more detailed basic description of phase diagrams and phase transitions.
IV - New advanced techniques. Fourth generation synchrotrons.
MAX IV: First fourth generation synchrotron light source in operation (21 June 2016) - Lund (Sweden)
▪ Max IV has a circumference of 528 meters, operates at 3 GeV energy, and has been optimized for high-brightness X-rays (Electron-beam emittance < 1nm.rad).
▪ There are also plans for a future expansion of the facility that would add a X-ray free electron laser (XFEL) to the facility, but is yet to be funded
MAX IV
Electron energy: 3 GeV
Emittance: 0.2 nm.radLNLS UVX
Electron energy: 1.37 GeV
Emittance:100 nm.rad
▪ In order to determine the detailed structure, without spatial averaging, the whole crystal should be considered as an "unit shell".
▪ This requires the use of an X-ray beam with a volume of coherence larger than the crystal volume.
▪ This coherence property allows for the analysis of the total set of relevant scattering intensities – over all accessible reciprocal space – which, through Fourier synthesis, leads to the whole material structure (and not the average structure of the unit cell).
▪ In other words, the use of coherent X-ray beams is expected to yield "lens-free images” of instantaneous structures of perfect and imperfect crystals, and even of amorphous materials.
Determination of local structures by usingfourth generation (very brilliant) X-ray sources
• The experimental setups used for lens-free X-ray imaging (without spatial averaging) require an incident X-ray beam with large longitudinal and transversal coherence lengths.
• The longitudinal coherence length is related to the monochromaticity of the X-ray beam and the transversal coherence length depends on the size of the photon source.
• Fourth generation X-ray sources with very low (diffraction-limited) emittance provide extremely bright X-ray beams that are expected to satisfy the coherence conditions for rather large sample volumes.
• In conclusion, the problems risen by spatial averaging of the structures of inorganic materials determined by classical X-ray diffraction, are starting to be solved by the use of very low emittance electron storage rings.
Coherence of X-ray beams emitted by fourth generation synchrotron sources
Phase
recovery
on
Coherent Diffractive Imaging
In situ Coherent Diffraction Imaging applied to catalysisFlorian Meneau, Ana F Suzana (PhD thesis), Amélie Rochet, Jean Rinkel
in collaboration with Ian Robinson, Diamond, UK
X-ray Coherent diffraction patterns of isolated (a)Au/Ag nanobox (b) the image of a nanobox with size ∼173 nm was reconstructed from the diffraction pattern.The scale bar is 100 nm.Takahashi et al. NanoLetters, 2013
3D ImagingIn situ, operando@ the single nanoparticle levelTowards nm resolution
Resonant Inelastic X-ray Scattering (RIXS)► RIXS is an X-ray “photon in- photon out” technique, meaning that one irradiates a sample with X-rays, and observes the scattered X-ray photons.
• HARD X-RAY
When F. Sette joined the ESRF, his goal was to build a IXS beamline with 1 meVresolution: the community was very sceptical. Quickly, the energy resolution achieved reached 1.4 ± 0.1 meV at 21.748 keV. ( ΔE/E = 6 x 10-8). Exciting results were obtained immediately on glasses and liquids[1] F. Sette et al, PRL. 75, 850 (1995)[2] G. Ruocco et al, Nature 379, 521 (1996).
• SOFT X-RAY: Braicovich, Ghiringelli, Brookes in 2004
Today
E(RX)=10KeV DE=0.1 meV
DE/E= 10-8 !!!
E(RX)=10000 eV
E (phonons) ~kT= 0.025 eV
E(phonons)/E(RX) = 2.5.10-5
Progress in RIXS resolution at the Cu L edge (931 eV).
(a) Ichikawa et al. [7], BLBB @ Photon Factory 1996
(b) Duda et al. [8], I511-3 @ MAX II, 2000
(c) Ghiringhelli et al. [9], AXES @ ID08, ESRF 2004
(d) Braicovich et al. [10], AXES @ ID08, ESRF 2009
(e) Braicovich et al. [11], SAXES @ SLS. Breakthrough: 130 meV!
(f) ERIX@ID32, 50 meV, ESRF 2015
(g) ERIX@ID32, 25 meV at the end of the year?
Soon NSLSII, Taiwan, Diamond, SLS...
SOFT X-RAY RIXS
←
RIXS spectra of La2CuO4 at CuL3 edge
•Since 30 years the maximum static pressure generated so far
at room temperature was reported to be about 400 GPa.
• L. Dubrovisky et al., Nature Comm.
2015 showed that the use of micro-
semi-balls made of nanodiamond
(10-50 μm) as second-stage anvils
allows to go above 600 GPa
•On rhenium and gold they have
studied the equation of state at
pressures up to 640 GPa and
demonstrated the feasibility and
crucial necessity of the in situ
ultra HP measurements for
accurate determination of
properties at extreme conditions.
•ONE NEEDS A VERY SMALL BEAMSIZE TO
MEASURE CORRECTLY THE PRESSURE
X-ray diffraction under extreme conditions (very high pressures)
High pressure
L. Dubrovinsky et al., Nature 2015: Powder diffraction of Osmium up to 774 GPa. By compressing Os,
one of most incompresssible metals, to over 770 GPa, they observed a new type of electronic
transition, the core-level crossing (CLC transition), that involves pressure-induced interactions between
core electrons, and leads to observable changes of the material properties. The ability to reach
sufficiently high pressure levels to affect the core electrons of transition metals in static high-
pressure experiments will open up opportunities in the search for new states of matter.
Atmospheric
pressure
DOS
P=392 GPa
Pressure at the
center of earth
Some remarks about the real possibilities opened by
the use of coherent X-ray scattering
V - New advanced techniques. Fifth generation light sources (X-ray free electron lasers).
LCLS
First X-ray FEL (2010)Stanford UniversityPalo Alto, California
▪ Very bright X-ray sources providing extremely short photon bunches named X-ray free electron lasers (XFELs) are currently in operation in USA (LCLS) and Japan (SACLA) and under construction in Germany (European XFEL).
▪ These new X-ray sources generate very short (~ a few tenths femtoseconds) photon bunches. The high power of the photon bunches rises an apparent problem because they completely destroy typical samples.
Features of the X-ray FELs
▪ Jet nozzle: 4 micron diameter producing nanocrystals in acqueousmedium (not dry as in electron microscopy nor at cryogenic temperature as in classical crystallography of nanoscopic samples)
▪ X-ray photon energy: 1.8 KeV (wavelength: 0.69 nm) ▪ Pulse duration: 10, 70 and 200 femtosec▪ Frequency of X-ray pulse repetition: 30 Hertz (1,800 pulses.sec)▪ Detector: 2 pn junction CPDs▪ Resolution reaches: 0.85 nm▪ Sample dimensions: ~ 200 nm▪ Number of X-ray diffraction patterns: 3,000,000▪ Number of useful patterns: 15,000▪ Spatial group: P63▪ a=b= 20.1 nm▪ c=16.5 nm
(88 authors !)
▪ Chapmen et al demonstrated experimentally that a single photon-bunch is sufficient for completely destroy a protein nanocrystal.
▪ In spite of this, since the photon-electron interaction is extremely fast, diffraction patterns associated to the initial structure of the nanocrystals (before being radiation damaged) can be recorded.
▪ Since in the mentioned investigation a single bunch was not enough for obtaining a diffraction pattern with good statistical quality, many (~104) protein nanocrystals were probed.
Serial Protein Crystallography
▪ The reported results demonstrated that the use of XFELs solves the old problem of radiation damage usually occurring in classical experiments of X-ray diffraction by protein crystals.
XRD pattern in detector 1 15.103 oriented and merged
XRD patterns, selected from 3.106 recorded patterns
(001) crystallographic plane
Structure determined by using a free-electron X-ray
laser by applying the multinanocrystal procedure
(0.85 nm resolution)
Serial crystallography Structure of a large membrane protein complex (MW: 1MDa)
Structure determined by classical synchrotron XRD data taken at 250 K and truncated at 0.85 nm resolution
XRD pattern in detector 2
The future of X-ray free electron lasers
The history of and experience with three generations of synchrotronradiation sources has taught us that the above experiments are atbest the tip of the iceberg of scientific opportunities.
It is safe to predict that we have not yet thought of the mostimportant experiments that eventually will be done with this newclass of radiation sources – x-ray free electron lasers!
Claudio Pellegrini and Joaquim Sthor
• The principle of Li batteries is based on the reversible insertion and extraction of Li-ions in the crystal structure of the positive (LiFePO4) and negative (Li) electrode materials
• Large volume changes, associated with phase transitions in the electrode material result in poor cycle performance by mechanical failure.
Why it is important to study them in real conditions (in situ)?
Because they are used in cell phones, portable computers, …
… and also in cars and air planes (This is more serious !)
In situ studies of Li batteries
• Microbeam X-Ray diffraction reveals for the first time the phase transformation in a large number of
(≈150) of individual electrodes grains (140 nm). Until now the particle-by-particle model, or mosaic
transformation mechanism predicts the absence of phase coexistence within individual grains.
• At C/5 (charge in 5 hours), a significant fraction of the (200) LFP and FP reflections during (dis)charge
appear as streaks inferring platelet-shaped domains having an average thickness of 37 nm. In addition,
the average transformation time of individual crystallites is 66 min for the LFP and 37 for FP, in contrast
with one minute predicted if assuming a surface reaction limited process.
Charging voltage
(C/5) including the
evolution of a 2D
(200) LFP and PF
peak (first order
Transition)
Az.
Direct view on the phase evolution in individual LiFePO4 (LFP)
nanoparticles during Li-ion battery cycling. X. Zhang et al., Nature Communications 23 September 2015. (ID11)
Real-time diffraction-topography setup for in situ studies of Si wafers
Rack et al.
Volume 3 | Part 2 | March 2016 | Pages 108–114 | 10.1107/S205225251502271X
White radiation from two undulatorsimpinges on a silicon wafer.
Both the 220 reflection topograph and the direct transmission image are recorded simultaneously.
Both imaging detectors are equipped with a high-speed camera in order to allow for a short exposure time (1.28 µs) and a high image-acquisition rate (∼35 500 images per second).
[Rack, A., Scheel, M. and Danilewsky, A. N. (2016). IUCrJ, 3, 108-114.
An (001) Si wafer with Vickers indent (dotted circles) at the centre. The edges correspond to the 110 directions.
(a) The 220 diffraction image with all the cracks, i.e. the final stage, acquired with 1.28 ms exposure time.
(b) The sum of 100 direct images corresponding to the final stage
Rack et al.
Volume 3 | Part 2 | March 2016 | Pages 108–114 | 10.1107/S205225251502271X
Real-time direct and diffraction X-ray imaging of irregular silicon wafer breakage
Selected images from a series of 3000 showing crack propagation in a silicon wafer under thermal stress (compare crack c1c in Fig. 2). (Left) The direct transmission images. (Right) The diffraction images with the 220 reflection.
Crack propagation
Rack et al.
Volume 3 | Part 2 | March 2016 | Pages 108–114 | 10.1107/S205225251502271X
Ds = 844 m
V = 3.108m/s
T = 844m/3.108 m/s = 2.8 ms
Dt (between bunches) = Dt/4 = 0.7ms
Four bunches
Exposure time: 1.28 ms
Acquisition rate: 35500 frames per sec
Time period between acquisition t = 38 ms
Exposure time: 1.28 ms
Propagation of the crack tip as derived from intensity profiles
Rack et al.
Volume 3 | Part 2 | March 2016 | Pages 108–114 | 10.1107/S205225251502271X
Crack tip
position
Time (ms)
Time
Crack tip
position
VI - New advanced facilities for investigations of materials in Brazil
Sirius-LNLS: Fourth generation synchrotron sourceX-ray diffraction and scattering, absorption and photoelectron spectroscopies
New LNLS synchrotron SIRIUSElectron energy: 3.0 GeVEmittance: 0.236 nm.rad
Former LNLS UVX synchrotronElectron energy: 1.37 GeV
Emittance: 100 nm.rad
Fourth generation light sources (synchrotrons) and
fifth generation light sources (XFELs)
Australian Synchrotron
Canadian4th generation light sources
▪ Lund, Sweden▪ Campinas, Brazil▪ Grenoble, France
5th generation light source
▪ Stanford, USA▪ Japan▪ Hamburg, Germany
Australian Synchrotron
Multipurpose Brazilian Reactor (RMB) (2020 - ?)
RMB
Iperó
LNLS
Campinas
Neutrons are particularly useful for structural studies of
magnetic materials, atomic structures of materials
containing low Z atoms and inelastic scattering (phonons
spectra). Techniques using neutrons also allow for modifying
the scattering power of selected elements by partial deuteration.
José Perrota, IPEN - Coordenador do Projeto
First Brazilian Neutron National Laboratory
Modern features of materials structure and properties.
A five dimensional problem
▪ In order to properly understand the static and dynamic properties of materials, the structural characterization can be considered as a vector with 5 components associated to:
3 spatial coordinates (X, Y, Z), time (T), and electronenergy (E).
▪ All five coordinates (X, Y, Z, T, E) can in principle be determined by using synchrotrons, neutron facilities and/or X-ray FELs by applying a number of different techniques: diffraction, diffuse scattering, absorption, reflectometry, and electron photoemission.
X
Y
Z E
T
“Five dimensional structure”
Materials properties
(Time)
(Electron energy)
VII - Challenges, future trends and final remarks.
X-ray laser–induced electron dynamics observed by femtosecond diffraction from nanocrystals of Buckminsterfullerene
B. Abbey + 21authorsScience Advances 09 Sep 2016:
Vol. 2, no. 9, e1601186DOI: 10.1126/sciadv.1601186
(A) Summed diffraction data 2500 single shots recorded at 100% power. The semitransparent red circle indicates the location of one of the reflections only observed in the 100% XFEL data. (B) Enlarged region from (A) showing Bragg peaks at 10% power, consistent with the room temperature FCC structure.
Comparing experimental and simulated data.(A) Schematic representation of the alignment of polarized C60 molecules. (B) Comparison of the 100% XFEL data and the model prediction based on the newly predicted, lower symmetry, structure. The black line shows the difference between the model and experimental data.
Laser-maximum powerLaser-medium power
Synchrotron
Until 1996: Classical X-ray generators for powder and single crystal structural investigations
X-ray diffractometers were available in many Brazilian laboratories from ~1960. SAXS setups were also used from ~1970 in IFSC, IFUSP and UNICAMP. Recently other laboratories receive new SAXS setups.
1997 – 2018 : LNLS UVX 1.37 GeV electron storage light source, Campinas
In 1997 the first Brazilian synchrotron light source UVX, a second generation 1.37 GeV electron storage ring, was open to users and is at present in operation at LNLS in Campinas.
2019 - … : LNLS 3 GeV Sirius electron storage light source, Campinas
In ~2019 a fourth generation 3 GeV electron storage ring SIRIUS (now in construction) will be available to users.
2022-… (?): A National Neutron Laboratory, associated to the Brazilian Multipurpose Reactor (IPEN) will be
open to users in Iperó –SP.This National Laboratory will provide neutron beams with much higher flux than those that are presently delivered by the beam lines installed at the reactor currently in operation at IPEN.
2025 - … (??) : Brazilian X-ray FEL (?)
The natural following step of LNLS after the first operation of SIRIUS will be to starting the a new project of a X-ray FEL.
X-ray and neutron sources in Brazil
▪ Many novel applications of modern coherent X-ray sources still require new and challenging developments of very stable optics, in situ preparation of nanoscopic samples, complex control systems, big-data analysis procedures and advanced instruments such as fast detectors with high spatial resolution and high dynamical range.
▪ Progresses related to these issues are being achieved so as the opening of the new LNLS synchrotron source (Sirius) to users is expected to bring new exciting and challenging research opportunities to Brazilian and international materials science communities.
The future. Challenges
Users of the forthcoming fourth generation synchrotrons and X-ray FELs
are expected to perform…
… new experiments that apply as much as possible their singular properties …
… avoiding to carry out research works only involving
“more of the same”!
(Quino cartoon)
Use of the forthcoming 4th and 5th generation X-ray sources
Not to do “more of the same” !
Use of the forthcoming 4th and 5th generation X-ray sources
Learn how to use !
… if we do not know how to properly use them, they will never be sufficient!
Independently of how good the “new tools” are and how many they are …
In order to achieve an efficient use of the forthcoming fourth and fifth generation X-ray sources for space
and time resolved structural characterizations, ...
... we, users, should learn the basic aspects related to the new
possibilities open by the modern X-ray sources and understand the
details of the associated experimental setup.
Some personal remembrances1964 - End of undergraduate studies in physics
at Instituto Balseiro, Bariloche, Argentina 1974 – Participation at the First Meeting of the Brazilian
Crystallographic Association, São Carlos - SP
1987 - With Cylon and Ricardo during the first year of activities at LNLS
2010 - With the new Director surrounded by scientists celebrating the 20th anniversary of LNLS Users Meeting
Acknowledgements
▪ Yves Petroff, Former Director of ESRF, Grenoble
▪ Massimo Altarelli, Director of European X-ray FEL, Hamburg
▪ Ricardo Rodrigues, Sirius Project Director, LNLS
▪ Harry Westfahl, Scientific Director, LNLS
▪ Helio Tolentino, LNLS
▪ Daniel Ugarte, Institute of Physics, UNICAMP
▪ Hannes Fischer, Jacto/FATEC, Pompeia - SP