Palestra plenária do XII Encontro da SBPMat (Campos do Jordão, setembro/outubro de 2013). Palestrante: Juan Andrés - Universitat Jaume I ( Espanha).

1. Connecting theory with experiment:
A survey to understand
the behaviour of multifunctional
metal oxides
Juan Andrés
Department of Physical and Analytical Chemistry, Universitat Jaume I,
Spain & CMDMC, Sao Carlos, Brazil
andres@qfa.uji.es

2. Despite the significant attention and numerous works devoted to
nano-sized materials, the physics and chemistry driving their
properties are sometimes not adequately explored.
Hence, understanding and controlling the properties of nanoscale
materials continue to be significant challenges to the scientific
community.
This is where theory and simulation come in to play.

3. The future of nanotechnology rests upon
approaches
to
making
new,
useful
nanomaterials and testing them in complex
systems.

5. The rapid increase is based on three pillars:
a)
In
modern
architectural
chemistry
manipulation
and
of
materials
science,
nanocrystals
with
the
well
precise
defined
morphologies and accurately tunable sizes remains a research focus
and a challenging issue because it is well-known that the properties of
the materials are closely interrelated with geometrical factors such as
shape, dimensionality, and size.
New preparation and growth methods allow one to
obtain nanomaterials in a controlled way.

6. b) By observing the microscopic structures of nanocrystals, insight
into growth mechanism may provide means to control nucleation, one of
the most secretive processes in nanoscience and nanotechnology.
Advanced
spectroscopies
and
microscopies
guarantee a characterization of nanomaterials at
the atomic scale.

7. c) Electronic structure theory has shown great value, not only in the
interpretation of experiments, but also in the prediction of new
properties and in the design of new devices.

8. Mark A. Johnson at Yale
two sides of physical
developed together, and
dictates the direction of
University discusses how the
chemistry have necessarily
looks at how their synergy
contemporary research.
Equations such as
Schrödinger‟s famous
contribution to quantum
mechanics underpin
much of physical
chemistry.
Nature Chemistry, 1, 8 (2009)

9. No single experiment reveals every detail and no
calculation is perfect, but the combination provides
the most profound and detailed insights to
understand and rationalize chemical/physical
properties and how we can control their finest
details.

10. Theory
Theoretical simulations of systems that represent
nanomaterials constitute one of the main tools in the
research for new nanomaterials.
Theory plays a role in the three stages of the development
ladder: characterisation, understanding and prediction.
Due to the complexity of the computational methods, there
is a strong need to integrate different models and cover
the relevant scales.
This requirement constitutes an important drawback as
scientists need training in several aspects of the problem
including chemical, physical and engineering views of the
modelling while keeping the experimental and industrial
interests and needs in perspective.

11. Experiment
Real
Word
Classification
Abstraction
Simplification
Approximation
Generalization
Experimental
Data
Theory
Applying
Theoretical Methods,
Computing Techniques
and Mathematical
Algorithms
Comparing is testing
Model of
the Word
Simulation
Predictions

12. Most suited techniques for the characterization of the electronic structure, crystal and local structures,
morphology, and composition of materials both at the macroscale and at the nano/microscale. The most important
contribution of DFT calculations to the interpretation of the different techniques is also shown.
Electronic Structure
Crystal Structure and
local structure
NMR (density of states DOS)
XANES, EXAFS (“oxidation states”, density of states)
XPS, AES (“oxidation states” and hybridation effects)
EELS (density of states)
NMR (local probe)
EXAFS (local probe)
EELS (DOS signature)
XRD, neutron diffraction
High-resolution TEM
DFT contributions
NMR (chemical shifts, simulated NMR spectra, density of states)
XANES, EXAFS (density of state)
XPS(density of state, electron density maps)
EELS (density of state, simulated ELNES)
NMR (chemical shifts, simulated NMR spectra)
DFT (structure optimization, electron density maps)
EELS (DOS signature)
Morphology
at the nano-microscale
Composition of the
bulk
Composition at the nano-microscale
SEM (micro, submicroscale)
TEM (nanoscale)
XRD (nanometer scale crystalites)
WDS
EDS
XPS
EELS
SEM-EDS (microscale, elemental mapping)
TEM-EDS (nanoscale, STEM elemental mapping)
TEM-ELLS (nanoscale, STEM)
Energy-filtered TEM (EFTEM)
XPS (X-ray Photoelectron Spectroscopy, AES (Auger Electron Spectroscopy, XANES/ EXAFS (X-ray Absorption
Spectroscopy), EELS (Electron Energy Loss Spectroscopy), NMR (Nuclear Magnetic Resonance), EDS (energy-dispersive
X-ray spectroscopy) WDS (wavelength-dispersive X-ray spectroscopy)
STEM (scanning transmission electron microscope), DFT (Density Functional Theory)

13. Here, we outline different published papers as well our work who
have propelled the field of Nanoscience and Nanotechnology, and then
I glimpse into their childhood years to see if there lays the key.
We restrict ourselves to methods that are firmly based on quantum
mechanics and it presents a subjective account of the research
conducted as collaboration between CMDMC/INCTMN at Federal
University of Sao Carlos (Brazil) and our Laboratory at UJI (Spain).

14. This talk examined three main areas:
(i) Surface structure as the key to manipulating the
physical and chemical properties as well as growth
mechanisms of nanomaterials.
(ii) Characterization of electronic excited states
understand and rationalize optical properties, and
to
(iii) Calculation of three dimensional electron density
distribution in materials, as an observable property,
determining in whole or in part their physical/chemical
properties.

15. (i) Surface Structure and Growth Processes
Investigation on nanocrystals growth is a rich field of research that
impacts on fundamental as well as applied science because the
importance of controlling nanostructural sizes and morphologies which
affects directly on the functional applications.
By observing the microscopic structures of nanocrystals, insight into
growth mechanism may provide means to control nucleation, one of the
most secretive processes in nanoscience and nanotechnology.

16. (i) Surface Structure and Growth Processes
As size of materials drops to nanometer size range,
interface/volume ratio increases, and , a greater proportion of the
atoms exist at the surface, increasing the ratio of
undercoordinated atoms ratio of unsatisfied surface bonds relative
to the bulk.
There is significant fraction of atoms associated with the
imperfection of the coordination numbers at the surface, which
induces their properties differently from their bulk counterpart
because of size effects.
As Wolfgang Pauli once famously said:
‘‘God made the bulk; surfaces were invented by the devil’’.

17. (i) Surface Structure and Growth Processes
Challenges
Accurate surface energy data are essential for calculating and
predicting the thermodynamic stability of nanosized structures.
From the perspective of thermodynamics, the growth of
nanostructures and the eventual morphology are driven by the
minimization of total free energies, which normally include surface
energy, elastic energy, electrostatic energy and so on.
Among them, anisotropic surface energy and high growth speed
along particular directions are often believed to underpin the
growth process.

18. METASTABLE COMPOUNDS
Illustration to show how mass transport coupled with pronounced
reorganization of atomic coordination environments is required in solidstate reactions forming new crystalline extended structures from solid
precursor phases. In this case, the two phases BaO and TiO2 react to
form the ternary oxide BaTiO3, which forms at the interface between
two reacting oxide particles; the particles are represented as cuboids
(BaO purple, TiO2 lilac, BaTiO3 green).
18
M. J. Rosseinsky, Angew. Chem. Int. Ed. 2008, 47, 8778.

19. CRYSTALLIZATION
How do crystals nucleate? According to classical nucleation theory, calcium carbonate
nucleation proceeds by addition of ions to a single cluster (top). Gebauer et al. now
suggest a different mechanism, in which nucleation of ACC occurs by aggregation of
stable, amorphous, precritical clusters (bottom). The nucleated ACC phase
subsequently crystallizes to generate the final stable crystal product.
F. C. Meldrum, R. P. Sear, Science 2008, 322, 1802.

21. Self-assembly
Nucleation
Crystal grwoth
Intermediate
crystal
Rise-like
Crystal
Crystal grwoth
Intermediate
crystal
Flower-like
Crystal
Crystal grwoth

22. Mesocrystals
Schematic representation of classical and
non-classical crystallization. (a) Classical
crystallization
pathway,
(b)
oriented
attachment
of
primary
nanoparticles
forming an iso-oriented crystal upon
fusing, (c) mesocrystal formation via selfassembly of primary nanoparticles covered
with organics.
H. Cölfen and M. Antonietti, Angewandte Chemie International Edition, 2005, 44, 5576-5591.

23. A. Menzel et al., J. Phys. Chem. Letters, 3, 2815 (2012)

24. JACS, DOI 10-1021/ja202184wl

25. CuO

26. 26

28. Defining Rules for the Shape Evolution of Nanomaterials
The morphology, shape and exposed facets of materials have been
shown to have a significant influence on their functional properties.
The understanding of the growth mechanism of nanoparticles is very
important for technological application, indeed growth control
might result in shape control, which is necessary to obtain
reproducible results.
The morphology, shape and exposed facets of materials have been
shown to have a significant influence on their functional properties.
Therefore the controlled synthesis of nanomaterial morphology and
structure (nanomorphology) is of vital importance.
Nanomorphology

29. Thermodynamic stability of the different surfaces is
associated to the surface energy of the crystallographic
orientations
Surface energy, Esurf
It is experimentally not trivial
to determine Esurf !!!

30. THEORETICAL FOUNDATION (1)
Reliable theoretical determination of Esurf from first
principles is of particular importance
Thermodynamic stability
1. At zero temperature Esurf can be derived from a slab calculations as follow
Esurf
N
lim Eslab
N
SnO
N·Ebulk 2 / 2 A
. Ebulk is the bulk cohesive energy per SnO2 unit formula
. Eslab is the total energy of a slab composed of N SnO2 units
. A is the area of surface unit cell
. the ½ factor comes from the fact that each slab has two surfaces

31. THEORETICAL FOUNDATION (2)
2. For SbxSn1-xO2 doped systems Esurf is calculated as follows:
Esurf
N
lim EslabSbx Sn1 xO2
N
SnO
N Ebulk 2
Sb
x Ebulk
Sn
Ebulk
/ 2A
. Ebulk is the bulk cohesive energy per SnO2, Sb or Sn unit
formula
. Eslab is the total energy of the slab
. N is the number of SbxSn1-xO2 units
. N·x is the number of Sn atoms substituted by Sb

32. THEORETICAL FOUNDATION (3)
Thermodynamic stability
3. The formation of macroscopic facets B of orientation (h2k2l2), and energy (per
unit area)
B
B
A
Esurf , on a surface A of orientation (h1k1l1), and energy Esurf
EA
surf
depends
of the sign of the formation energy:
E
A
Esurf h1k1l1 cos
B
Esurf h2k2l2
is the angle between the planes, cos
surface area if facets were formed
Wulff equation
takes into account the change in
If
E < O, the growth of facets B on A is stable,
If
E > O, their formation is unstable

33. THEORETICAL FOUNDATION (4)
Thermodynamic stability
4. According to the Wulff equation, the crystalline morphology can be
predicted from the surface energy of different faces. Thus, the crystalline
form can be derived from a construction in which the distance between a
facet and an arbitrary point is proportional to the surface energy of the
respective crystallographic plane
Wulff construction
Rutile (TiO2)
Anatase (TiO2) (a) calculated, (b) Crystal sample

34. Nanoribbon with rectangular cross section
Narrow facet
(010)
Wide facet
_
(101)
Growth direction
[101]

35. The high-resolution transmission electron microscopy, HRTEM, allows the
investigation of the nanomaterials‟ microstructures.
The calculation of surface energies, Wulff construction and HRTEM images,
allowed us to modelize the preferential growth directions ofSnO2 nanobelts
(010)
Narrow
facet
(101)
Growth
direction
_
(101)
[101]
Wide
facet
(a) HRTEM image perpendicular to
_
the (101) face of a SnO2 nanobelt
[8] A.
(a) Proposed model for the SnO2 nanobelts
Beltrán, J. Andrés, E. Longo, E. R. Leite, Appl. Phys. Lett. 83, 635, 2003

36. In our calculations the order of increasing
energy is:, (110) < (100) < (101) < (001). Since
the (110) and (001) surfaces have the lowest
and
the
highest
surface
energies,
respectively, and the [001] direction is the
favored growth direction and should result
in particles with a high aspect ratio.
The experimental findings[9] for SnO2
nanorods agree very well with our
calculations, i.e., the single-crystalline
nanorods show a mean aspect ratio of ~ 4:1
with the [001] direction along the major
axis.
[001]
[110]
Single-Crystalline SnO2 Nanorods
[9]
E. T. Samulski et al. J. Am. Chem. Soc., 126 (19), 5972 -5973, 2004

37. Wulff construction
3.00
172.4
Calculated surface energies and derived Wulff construction for pure SnO2 (rutile)

38. HRTEM Image Simulation for (001) Faceting
Atomic arrangement of ATO nanocrystals with different (001) faceting and
their respective simulated HRTEM images along the [111] zone axis.
These results show that the contrast at the edges of the HRTEM simulated
images is strongly dependent on the (001) facets dimension.

39. Proposed and actual ATO nanocrystals observed along the [111] zone axis.
a) proposed ATO nanocrystal habit superimposed on its Wulff construction.
b) Multislice simulated HRTEM image obtained from the proposed nanocrystal habit.
c) Comparison of the nanocrystal multislice simulated HRTEM nanocrystal image and
d) the experimental HRTEM image.

40. Oriented attachment evaluation
Predicted oriented attachment configurations for the modeled ATO
nanocrystal for (a) (100), (b) (001), (c) (101), and (d) (110) facets.

41. Figure 3. FEG-SEM micrographs of PbMoO4 micro-octahedrons processed by
hydrothermal method at 100oC/10 min (a, b) PMO/ACC and (c,d) PMO/PVP.

42. Figure 4. Schematic representation of the synthesis and growth mechanism for
PbMoO4 crystals by FEG-SEM (a) without surfactant, (b) with acetylacetone (ACC) and
(c) polyvinylpyrrolidone (PVP).

44. 
Schematic process of CTO
Microwave-Assisted
Hydrothermal sinthesis.

46. Fig. 5 FE-SEM images and schematic model to illustrate the synthesis
and assembly of STO as cubes.

47. Characterization of electronic excited states
understand and rationalize optical properties
to

48. Nanoparticles in Retrospect
Helmut Goesmann and Claus Feldmann Angew. Chem. Int. Ed. 2010, 49, 1362 – 1395

50. C. Feldmann, Nanoscale, DOI: 10.1039.clnr90008k

52. J. Phys. Chem. C 2012, 116, 11849-11851

53. Continuum
Conduction
band
Eg
Valence
band
Trap state
manifold
Electronic
Excited
States

54. ABO3 Structure
Clusters [BO6] and [AO12]

55. Perovskite Based Materials
The ideal ABO3 perovskite structure

56. While the concept of a crystalline solid as a
perfect, periodic structure is at the core of
our understanding of a wide range of material
properties, disorder is in reality ubiquitous,
and is capable of influencing various properties
drastically.
Our understanding of the atomic structure of
materials relies on our ability to describe
structural characteristics such as the shortrange order or the periodicity inherent to
crystalline materials.

58. Probing Local Dipoles and Ligand Structure in BaTiO3 Nanoparticles
K. Page, T. Proffen, M. Niederberger, R. Seshadri
Chem. Mater. 2010, 22, 4386
Depictions of TiO6 octahedra in the (a) cubic (b) tetragonal (c)
orthorombic and (d) rhombohedral structures.
Ti displacements have been exaggerated for clarity.

59. We exemplify the potential of this concept in
the optical properties (photoluminescence and
radioluminescence) of perovskite and scheelite
based materials.

60. [SrO12]
[TiO6]

61. Cubic to tetragonal
s → 261 cm-1 en las 3D
t* → 365 cm-1
Sr
Ti
O
s* → 336 cm-1 en c

62. TiO2 Anatase
Normal vibrational modes in cm-1
s
Eg
169
101
R
Eg
206
237
R
Eu
286
201
IR
A2u
394
362
IR
B1g
c
s*
408
379
R
Eu
445
391
IR
c
b
b
a
a
b
Structural data
s
s*
a
3.7991
3.9182
B1g
530
503
R
c
9.6929
9.7226
B2u
566
542
IR
u
0.2057
0.2065
A1g
639
627
R
1.947(4)
2.004(4)
Eg
656
577
R
1.994(2)
2.008(2)
dTi-O

63. (iii) Calculation of three dimensional electron
density distribution in materials, as an observable
property, determining in whole or in part their
physical/chemical properties.
The electron density distribution in a system
determines its stability, geometry, physical/chemical
properties and reactivity, in short its chemistry.

64. Theory
Charge density [ (x,y,z)] defines the structure and
chemical and physical properties of the compound

65. We need a little history
“Chemistry is a consequence of the short-range nature
of the one-electron density matrix that determines all
the mechanical properties of an atom in a molecule with
the additional important proviso that all of the necessary
physical information is obtained in its expansion up to
second-order with regard to both the diagonal and offdiagonal terms” .
R. F. W. Bader, Atoms in molecules: a quantum theory, Oxford
University Press, Oxford UK 1990.
R. F. W. Bader, Int. J. Quantum Chem. 1995, 56 409–419.

66. The electron density, ρ(r), is a fundamental Dirac
observable that defines completely the ground state
of an electronic system.
Hohenberg, P.; Kohn, W. Phys. Rev. 1964, 136, B864–B871.
In this regard, an experimental or theoretically
determined charge density yields a wealth of
information about the electronic structure of atoms,
molecules, and solids.
Koritsanszky, T. S.;Coppens, P. Chem. Rev. 2001, 101, 1583–1628.
Coppens, P. “The interaction between theory and experiment in
charge density analysis” Phys. Scr. 87, 2013, 048104

67. Experiment and Theory
(r)
Retrieving all information from quantum mechanical wave function

68. Bader’s Quantum Theory of Atoms in Molecules
(QTAIM), in which he put the main emphasis on the
charge distribution ρ(r), represents one of the
pioneering efforts of this new school of thought.

69. In particular, the topological analysis of ρ(r) has
enabled the development of a theory of molecular
structure, which has proven useful in the study of a
diverse range of chemical phenomena.
Bader, R. F. W. Atoms in molecules: A Quantum Theory; Oxford
University Press: Oxford, UK, 1990.

70. QTAIM goes far beyond a simple topological study of a
scalar field.
It rather provides a full consistent quantum mechanical
framework for the definition of the atoms or group of
atoms in a molecule or crystal and for the treatment
of the mechanics of their interaction.
C. Gatti in “Challenging chemical concepts through charge density of
molecules and crystals” Phys. Scr. 2013, 87, 048102

71. A bridge for fertile research
Topological analysis of ρ(r) provides a mathematical bridge
between quantum mechanics and chemistry/physics.
Thanks to this machinery, it is possible to correlate
topological properties of ρ(r) with elements of molecular
structure (atoms and bonds), making quantum chemistry
concepts compatible with traditional chemical/physical
ideas.

72. Nature Scientific Reports, 3, 1676-1680 (2013).

73. Here we focus primarily on two main aspects: structural and electronic
properties in order to answer three central questions:
What happens with the electron excess as it approaches the surface and
bulk of –Ag2WO4?
How are the electrons distributed in this material and how can it is related
with the structural and electronic evolution?
Can QTAIM properties tell us anything about the strength of the bonds after
electron irradiation on –Ag2WO4?
Specifically, we have studied the geometric and electronic structure of –
Ag2WO4, and then we have derived a mechanism produced in the scenario of
electron irradiation of AgOx (x= 2, 4, 6, and 7) and WO6 clusters, as constituent
polyhedra of –Ag2WO4, relevant to formation and growth of Ag filaments.

74. An electron beam of high energy electrons generated
within transmission electron microscopy (TEM) is
employed to obtain high-resolution imaging, as well as to
observe and confirm elemental and crystal structure on
single nanoparticles.
However, it is well known that electron beam causes
considerable changes in the physical and chemical
properties, and lead to the formation of unexpected
and very exciting structures in nanoscale materials.

75. e- irradiation
100 ºC
Growth of Ag
nanofilaments
120 ºC
FESEM images
Electron beam radiation guides the growth process of Ag nanofilaments on -Ag2WO4

76. -Ag2WO4
Ag
3
Ag4
Ag1
Ag2
W1
W3
[AgO6 ] Distorted Octahedra
Ag4
Ag5
W2
Ag1
[AgO7] Distorted Triangular
Prismatic
Ag3
Ag2
Ag6
Ag5
Cluster
[AgO4 ] Distorted Tetrahedra
Ag6
[AgO2 ] Twofold
W1
W2
W3
[WO6 ] Distorted Octahedra
b
c
a

77. Distance range (Å)
VASP
(PBE+U)
2.33 - 3.04
2.34 - 3.04
2.28 - 2.58
2.23 - 2.44
2.23 - 2.44
2.14
1.83 - 2.11
1.80 - 2.23
1.80 - 2.23
Ag1
Ag2
Ag3
Ag4
Ag5
Ag6
W1
W2
W3
Cluster
[AgO7] Distorted Triangular Prismatic
[AgO6 ] Distorted Octahedra
[AgO4 ] Distorted Tetrahedra
[AgO2 ] Twofold
[WO6 ] Distorted Octahedra

78. Plane (100)
NANODOMAINS
N=0
N = 10
W3
W3
108.44o
91.77o
Ag4
Ag4
168.46o
170.47o
Ag6
Ag4
178.21o
179.77o
Ag5
175.38o
Ag6
179.02o
Ag5
Ag5
107.43o
90.26o
W2
W2
Ag4
Ag5

79. Plane (100)
Charge Density
N=0
N = 10
W3
W3
1.2 a.u.
Cluster
Ag4
Ag5 [AgO4 ] Distorted Tetrahedra
Ag4
Ag4
Ag6
Ag6
Ag5
Ag5
0.0 a. u.
W2
W2
Isodensity lines < 0.02 a. u. are coloured in white
Isodensity lines > 0.02 a. u. are coloured in black
Ag6 [AgO2 ] Twofold

80. Bader population analysis
q ( ) = Z - N (( )
[WO6] (W1)
2.8
Atomic charge, q ( )
2.6
N( )=
( ) dr
Tungsten
0.8
2.4
0
1
2
0.6
3
4
5
6
7
8
Silver
0.4
0.2
[AgO4] (Ag4/Ag5)
0
Silver is reduced!!!!!
[AgO2] (Ag6)
-0.2
0
1
2
3
4
5
6
Number of electrons
7
8
9
10

81. ~~
2.9
2.8
distance Ag-O/ W-O (Å)
2.7
2.6
[AgO2] x2
2.5
[AgO4] x2
[AgO4] x2
2.4
[WO6] x3
2.3
[WO6] x1
[WO6] x2
2.2
2.1
2
1.9
1.8
0
1
2
3
4
5
6
Number of electrons
7
8
9
10

82. AIM analysis
Laplacian
BCP = Ag-O bond critical point
2
Bond Density
BCP [AgO2]
Ag-O1
b
BCP [AgO4]
Ag-O
b
Ag-O2
Ne
Density
Laplacian
Density
Laplacian
Density
Laplacian
0
0.49
6.80
0.26
3.29
0.42
4.91
1
0.42
4.56
0.23
2.93
0.39
4.35
2
0.34
3.88
0.21
2.67
0.35
3.86
3
0.26
3.10
0.20
2.56
0.28
3.10
4
0.20
2.26
0.19
2.35
0.22
2.56
5
0.17
1.84
0.16
1.96
0.19
2.17
6
0.17
1.76
0.15
1.83
0.19
2.08
7
0.16
1.71
0.13
1.65
0.19
2.12
8
0.14
1.55
0.12
1.39
0.17
1.80
9
0.14
1.47
0.10
1.23
0.17
1.76
10
0.13
1.40
0.10
1.14
0.16
1.51

83. The Ag formation on
–Ag2WO4 is a result of the
order/disorder effects generated in the crystal when
electron irradiation provokes a structural and electronic
rearrangement within it.
Both experimental and theoretical results point out that
this patterning was due to structural and electronic changes
of the AgO2 and AgO4 clusters and in minor extent one WO6
cluster, as constituent building blocks of –Ag2WO4.

84. S t a t u s a n d m o v i n g f o r w a r d
More basic understanding–theory-simulation-experiment
Key role of quantum mechanics; Recent advances of quantum chemistry show
the applicability of quantum chemical theory in Nanotechnology.
Integration of the conceptual framework for understanding:
i) Structure, physical/chemical properties and chemical reactivity
ii) Heterogeneous, homogeneous and enzyme catalysis
iii) Size and shape dependent properties at nanoscale
iv) Fundamental and excited electronic states
v) Photocatalytic, degradation, and antimicrobacterial proceses
Better coupling of design and process engineering

85. P r o m o t i n g
D e v e l o p m en t
An integrated approach:
Experiments, models
Synthesis
Testing
Characterization
Theory

87. „„The important thing in science is not so much to
obtain new facts as to discover new ways of
thinking about them‟‟
William Henry Bragg
“We can't solve problems by using the same kind
of thinking we used when we created them.”
Albert Einstein

88. In this presentation, some of the critical challenges for
the field of Nanotechnology and Nanoscience are
discussed.
Three main guides are fundamental in our research:
(a) Instigating creativity, innovation, and questioning
scientific assumptions
(b) Instigating interdisciplinary research
(c) Bringing
experiments
together
theory,
simulations,
and

89. A broad team is necessary to probe this type of physics
and chemisty. It takes a high level of expertise in materials,
measurement, characterization, theory, simulation, and
calculation that is not often found at one institution.
It is the depth of talent at CMDCM and ability to easily
work with researchers in other areas that made these
achievements possible. The resulting cross-fertilisation
between disciplines has already yielded an awesome
cornucopia of multitasking devices, and no doubt the best is
yet to come.

90. Acknowledgments
Prof. Jose A. Varela, Prof. Elson Longo, Prof. Edson Leite
Dr. Mario Moreira, Dr. Valeria Longo, Dr. Diogo Volanti,
Dr. Laecio Cavalcante, Dr. Marcelo Orlandi, Dr. W. Awansi,
Dr. Y. Santana,
Felipe Laporta, Amanda Gouveia, Matheus Ferrer
(CMDCM, Sao Carlos and Araraquara, Brazil)
Prof. Armando Beltrán, Dr. Lourdes Gracia, Dr. Silvia Ferrer, and
Dr. Patricio Gónzalez-Navarrete,
(Universitat Jaume I. Castelló. Spain)
Dr. Valmor R. Mastelaro and Dr. Luis F. da Silva (Sao Carlos)
Dr. Mauricio Bomio (Natal)
Dr. Fabricio Sensato (Sao Paulo)
Dr. Daniel Stroppa and Dr. Antonio Ramirez (Campinas)
Dr. Julio Sambrano (Bauru)
90

91. Acknowledgments
Brazilian agencies Fapesp and CNPq by the financial support.
91

92. Acknowledgments
Spanish research funds provided by
Ministerio de Economia y Competitividad of the Spanish Government,
Generalitat Valenciana (Prometeo Project), and
Programa de Cooperación Científica con Iberoamerica
92

93. Newton‟s remark that we are
“dwarfs in the shoulders of giants”
is as valid as ever, and Prof. Elson Longo was
certainly one of those giants.

94. Dedicatoria
Dedico, sinceramente, esta apresentação
amigo e Professor Elson Longo.
ao
Tive o grande prazer de conhecê-lo em 1988 e deste então
nossa amizade tem-se intensificado ao longo dos anos.
Poucas pessoas irradiam entusiasmo e confiança como ele.
Uma pessoa com primorosa experiência de vida – pessoal e profissional.
Trata-se de um homem com uma lucidez e generosidade inusuais,
extraordinariamente amável, aguerrido e rigoroso cientificamente.
Uma bela pessoa e um grande pesquisador, que tem uma visão privilegiada
das relações interpessoais, dos processos de ensino-aprendizagem e da
inovação tecno-científica.

95. Dedicatoria
De suas experiências, aprendi que os países não
son suas bandeiras, hinos ou línguas, mas sim
lugares e pessoas que povoam nossas recordações
e nos enebria de nostalgia, que nos confere a
fraternal sensação que teremos sempre um lugar
aconchegante ao qual sempre podemos retornar.