Scientific Program

Conference Series Ltd invites all the participants across the globe to attend 10th International Conference on Emerging Materials and Nanotechnology Vancouver, British Columbia, Canada.

Day 3 :

  • Track 3: Advanced Emerging Materials
    Track 5: Materials: Characterization and Applications
Location:
Speaker
Biography:

Mattheus (Theo) F. A. Goosen has played key roles in the development of new start up academic institutions. For the past nine years he has held the position of founding Associate Vice President for Research & Graduate Studies at Alfaisal University a private start-up non-profit institution in Riyadh, Saudi Arabia (www.alfaisal.edu). The doctoral degree of Dr Goosen is in chemical & biomedical engineering from the University of Toronto (1981) Canada. Theo has more than 180 publications to his credit including over 133 refereed journal papers, 45 conference papers, 10 edited books and 10 patents.  His h index is over 47 and he has well over 8000 citations on Google Scholar. On Scopus he has 133 publications with over 4000 citations. Dr Goosen’s research interests are in the areas of renewable energy, desalination, sustainable development, membrane separations, spray coating technology and biomaterials.

Abstract:

Statement of the Problem: Nanoindentation of WC-12Co thermal spray coatings has been used to evaluate the elastic modulus and hardness of coating on the polished surface of the coatings. While there has been much progress overall, limited research has been reported on the deposition and evaluation of WC-cermet coatings. The aim of this study was to evaluate the microstructural and nanohardness characteristics of tungsten carbide-cobalt (WC-Co) cermet coatings deposited by liquid suspension spraying. Methodology: Commercially available WC-Co coating powder was milled and water based suspension was produced as feedstock for the thermal spray coating process. Microstructural evaluations of WC-Co cermet coatings included XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscopy). Post spraying nanomechanical evaluations were conducted using a Berkovich nanoindenter.  Findings: Results indicated relatively higher modulus but lower hardness of suspension coatings. The load displacement curves during nanoindentation were characteristic of the complex coating microstructure showing signs of microcracking and pile-up. The load displacement (P-h) curves along with the SEM images of indents for S-HVOF (suspension high velocity oxyfuel) coating illustrated evidence of sink-in and pile-up of material around the indent contact residual impression during the nano-indentation process. There was some indication of microcracking during indentation as well.

Conclusions: A comparison of S-HVOF and conventional HVOF coatings points toward phase transformations occurring in the suspension spraying which led to nanocrystalline or amorphous phases. The elastic modulus of S-HVOF coatings was on average higher than the conventional HVOF coating. The load displacement curves show features which are consistent with the complex coating microstructure with evidence of micro-cracking and pile-up.

Speaker
Biography:

Research Experience (some events): Dec 1999 – Aug 2016 Research Director, Czestochowa University of Technology, Institute of Computer Sciences Czestochowa, Poland. Oct 1994 – Sep 2002.Professor in Full, Jagiellonian University, Institute of Physics, Cracow, Poland. Visiting Scientist -  Integrability of quantum systems, Universiteit Utrecht, Institute for Theoretical Physics Utrecht, Netherlands. Jul 1988 – Sep 1988 Visiting Scientist - Dynamical critical phenomena Universiteit Utrecht, Institute for Theoretical Physics. Apr 1988 – Apr 1988 Visiting Professor - Phase transitions and critical phenomena - lectures for PhD students, The Rockefeller University, New York City, United States Laboratory of Mathematical Physics. Feb 1988 – Oct 1994, Professor (Associate),   Head of Soft Condensed Matter Department, Jagiellonian University, Institute of Physics, Kraków, Poland.

Abstract:

Certain features of certain materials are self-similar. This phenomenon is recognizable by scaling of measurement data corresponding to the considered self-similar feature. To perform scaling we apply notion of homogenous function in general sense. For two independent variables such a function reads P(f,B)=Bβ F(f/Bα), where P is a considered magnitude, α and β are scaling exponents, F(∙) is an arbitrary continuous function, where α, β and F(∙) have to be determined by the measurement data. Definition of P(f,B)  enables us to transform all  characteristics P(f,B) to the one universal function of the one variable: P(f,B)/ Bβ =F(f/Bα ). This effect is so called the data collapse and can be applied for comparison of measurement data measured in different laboratories, which enable us to estimate quality of each laboratory series. Another application of the data collapse is compression of large experimental data. If the considered data are produced by a self-similar system then one can store them in a form of continuous curve. The data collapse enables us to introduce an absolute dimensionless characteristic:

1), where P and f are dimensionless P and f, respectively. This characteristic divides { P, f } space into the two independent subspaces of materials’ characteristics.

Finally, the scaling supplemented by pseudo-equation of states plays basic role in creation of algorithms for designing of modern materials.

 The presented results base on experimental data of Soft Magnetic Materials and Soft Magnetic Composites. Where, P(f,B) is density of power loss, f is frequency of the field’s modulation and B is maximum of magnetic induction. One can apply this simple mathematics to any self-similar object. However, ultimately one must say that the degree of success achieved when applying the scaling depends on the property of the data. The data must obey the scaling.

Speaker
Biography:

Dr. Ohmura is a professor of Osaka University.  His main field of research is intelligent laser processing systems, especially theoretical analysis and computer simulation to gain deeper understanding of the complicated physical phenomena in laser material processing, influence of laser optics, and nonlinear optical phenomena.

Abstract:

When laser beam with a high energy density is irradiated onto a material, the energy of the beam is converted into thermal energy by absorption, and the temperature rises locally.  Thermal diffusion occurs due to a steep temperature gradient.  However, as the thermal diffusion time and the thermal diffusion length are very short, a phase change such as fusion, evaporation, sublimation, occurs instantly because energy is added locally in a very short time.  The thermal stress caused by this temperature gradient is large and as a result, hard and brittle materials that are difficult to process by mechanical processing can be processed by non-contact processing.  Two examples of laser assist break of hard and brittle materials are introduced here.  (1) Stealth dicing of the silicon wafer:  A permeable nanosecond pulse laser is focused into the interior of a silicon wafer and scanned in the horizontal direction, causing a belt-shaped modified layer to be formed in the wafer (Fig. 1).  Applying tensile stress perpendicularly to this modified-layer separates the silicon wafer very easily into individual chips.  This method is called “stealth dicing (SD)”.  In order to establish a more highly reliable dicing technology and investigate the optimum processing conditions, the formation mechanism of the internal modified layer was studied (Figs. 2 and 3).  (2) Laser scribing of glass:  Glass sheet is used for flat panel displays, and laser scribing is being used as the separation process.  We conducted thermal stress analysis and crack propagation analysis in order to clarify the processing phenomena and control factor.

   

Speaker
Biography:

Klaus G. Nickel is Professor for Applied Mineralogy at the Faculty of Science of the University of Tübingen. His career involved a Dipl-Geol. from the University of Mainz (D), a PhD from the University of Tasmania (Hobart, AUS) and research positions at Max-Planck-Institutes (for Chemistry, Mainz, and Metals Research, Stuttgart). His main research interest is in materials science in the field of advanced ceramics and composites. The research covers processing, characterisation and evaluation of technical ceramics, typically alumina and zirconia in the oxides and carbon, carbides, nitrides, borides on the non-oxide side. Particular expertise exists in the chemical property evaluation (oxidation and corrosion). Other research goals are phase relations, mechanical properties and bionics of biomaterials and ceramics.

Abstract:

The design of spines from some reef inhabiting sea urchins (Heterocentrotus mamilatus, Phyllacanthus imperialis) has been shown to be responsible for a high energy dissipation during compressive straining. It is shown that unusually high stresses are required to compress the material, which fails in a "graceful" manner during an overall straining of several tens of percent. The principal behind the mechanism involves the layering / gradation / ordering of pore space within a basically brittle material (Calcite). We will show the details of the structures and the results of the characterization by uniaxial compression and pin indentation. The natural material has a hierarchical design including a structuring on the nano-scale to prevent a failure by simple cleavage. It would therefore be difficult to scale up all structural features of this brittle material. We will discuss how improvements of material can nonetheless be implemented by abstracting only the more macroscopic features and choosing a suitable material.

First efforts to apply this biomimetic principle to concrete as a modification of functional graded concretes confirm the effectiveness in construction materials. The design is not only beneficial for failure tolerance in cases of impacting objects but improves at the same time thermal insulation properties and lowers the total weight of constructions.  The concrete was realized by spraying and slip casting methods. We will also present a recently developed alternative method for the manufacture of 3D concrete constructions (“hydroplotting”), which allows the realization of very detailed designs. 

Speaker
Biography:

Lahcène Ouahab received his PhD thesis from the University of Rennes1 in 1985. He was “Maître de conférences” at the University of Constantine (Algeria) and then associate Professor at the University of Rennes1 (1988) before getting a permanent position in CNRS as “chargé de recherche” in 1989. He is presently a CNRS director of research and leads the molecular materials research group. He was director of the  “Laboratoire de Chimie du Solide et Inorganique Moléculaire UMR6511-CNRS Université de Rennes1” 2004-2006. He was awarded the 1998 prize of the Coordination Chemistry Division, the 2011 Claude Berthault Prize of the “Académie des Sciences” and the 2012 “Grand Prix Pierre Süe” of the French Chemical Society. His fields of research include molecular materials, in particular, multifunctional materials, charge transfer complexes, radical ion salts, organic-inorganic hybrids, polymeric coordination complexes and polyoxometallates

Abstract:

last decade and more particularly in the branch of single molecule magnets (SMMs). The main reasons are their large magnetic moments associated to their intrinsic large magnetic anisotropy. The splitting of the multiplet ground state of a single-ion in a given environment is responsible of the trapping of the magnetic moment in one direction in SMMs. However, the analyses of the crystal field effects on the magnetic anisotropy are not so common. A better understanding of the magneto-structural correlations in lanthanide-based complexes should provide tools to improve their potentialities. In this presentation we will focus on the specific magnetic properties of TTF-based lanthanide mononuclear and polynuclear complexes. We will show how optimize the SMM behavior playing on i) the modulation of the supramolecular effects via chemical modifications of the TTF ligand, ii) simple molecular engineering modifying the electronic distribution and symmetry of the coordination polyhedron, iii) magnetic dilutions (solution and doping) and iv) isotopic enrichment of the dysprosium.

Speaker
Biography:

Haruhiko Morito has his expertise in material science and engineering. The main objective of his research is to develop an emerging material which has a new function and new physical properties. In particular, he has developed new functional ceramics containing alkali metals. He has also developed a new crystal growth process based on the binary phase diagram of sodium and silicon. He has synthesized the various silicon-based materials by the sodium flux method.

Abstract:

Introduction: Si clathrate compounds have been widely studied due to their unique open-framework structures of Si polyhedrons. Two types of Si clathrates encapsulating Na atoms have been known: type I (Na8Si46) and type II (NaxSi136, 0 < x ≤ 24). These Na-Si clathrates have been generally synthesized by thermal decomposition of a Na-Si binary compound, Na4Si4, at 673–823 K under high-vacuum conditions (<10−2 Pa), and the obtained samples were in the form of powder with a particle size in the micrometer range. The purpose of this study is the crystal growth of the type I and type II Na-Si clathrates by using a Na-Sn flux. Experimental: The starting material of a mixture of Na, Na4Si4, and Na15Sn4 was prepared by heating Na, Si, and Sn (molar ratio, Na/Si/Sn = 6:2:1) at 1173 K in Ar atmosphere. The mixture was heated at 673–873 K for 6–24 h in the container with a temperature gradient. After heating, air-sensitive compounds in the samples, such as Na-Sn compounds, were reacted with ethanol, and the water-soluble reactants were removed by washing with water. Sn present in the products or formed by the ethanol treatment was removed by dissolution in a dilute nitric acid aqueous solution. Results: The single crystals of type I clathrate were crystallized due to the evaporation of Na from the Na-Sn-Si solution at 673–773 K. Most of the single crystals had sizes of several hundred micrometers to 1 mm, and the maximum size reached to about 3 mm. Heating the starting mixture at 823–873 K resulted in the crystal growth of the type II clathrate. The single crystals having {111} habit planes grew up to about 2 mm in size as shown in Fig. 1.

Speaker
Biography:

Ki-Soo Lim is a full professor of physics department at Chungbuk National University in South Korea. He has been working on laser spectroscopy of rare-earth ion doped crystals, glasses, glass-ceramics, and semiconductors. He also studied 3-D bit or holographic data storage in glass, photopolymers and photovoltaic materials. Recent interests and achievements include precipitation and optical properties of glass-ceramics containing fluoride nanocrystals, and micro-nanostructure fabrication on the surface of dielectric materials and polymers by femtosecond laser. He received his B.S. and M.S. degree in Physics at Seoul National University in 1977 and 1980 respectively. He then did his PhD in physics at University of Connecticut, USA, and worked at University of Georgia as a research associate. He joined Chungbuk National University in 1990 after working at Korea Standard Research Institute. 

Abstract:

We report the self-formed nanogratings on the surfaces of semiconductors (ZnO and GaN) and dielectric materials (fused silica, borate glass, LiTaO3, LiVO3, sapphire) prepared by scanning focused femtosecond laser pulses at 800 nm with a repetition rate of 1 kHz. Laser fluence range for nanograting self-formation is very narrow. We find a series of periodic-structure orientation is perpendicular to the linear laser polarization. The period of grating structures on the dielectric surface depends on laser power and scan speed, and increases in the range of 200∼300 nm with scan speed and laser pulse energy. In contrast, GaN shows about 600 nm period in the same power range as the dielectric materials. Its period decreases to 450 nm when the laser power is reduced ten times. It also has much lower laser ablation threshold than dielectrics and ZnO, indicating characteristics of metal-like nanogratings due to its high plasma density, large thermal conductivity, and multiphoton absorption coefficients at 800nm. Emission from nanograting area of sapphire indicates the existence of oxygen vacancies. Figure 1 shows the nanograting structure formed by scanning femtosecond laser pulses at 40 μm/s speed of on the surfaces of LiVO3 and ZnO with 0.13 and 0.09 mW power respectively.

For applications, surface nanostructures can be used to improve out-coupling of light in LED. Material absorption can be also significantly enhanced due to surface nano-structures produced by fs-laser pulse processing, applicable to sensing and solar cells.

Speaker
Biography:

Yutaka Wakayama served at Asahi Glass Company, as a research engineer from 1989 to 1994. He was a research staff member at Tanaka Solid Junction Project, ERATO, JST from 1994 to 1998, and received his Ph. D degrees from University of Tsukuba in 1998. After working as a postdoctoral fellow at Max-Planck Institute for Microstructure Physic, Germany in 1998-1999, he joined National Institute for Materials Science (NIMS) in 1999. Now, he belongs to International Center for Materials Nanoarchitectonics (WPI-MANA) of NIMS. His current research interests are self- and directed-assemblies of molecules, functional organic field-effect transistors and molecular nanoelectronics.

Abstract:

We developed an optically controllable organic field transistor (OFET) by employing photochromic diarylethene (DAE) molecules as a transistor channel layer. DAE molecules are known to undergo photochromic reaction, i.e., reversible conformational change between closed- and open-ring isomers by alternating ultraviolet (UV) and visible (VIS) light irradiation. We found that the drain current in the DAE-based OFET also showed reversible change accompanied by this conformational change; the closed-ring isomer produced by UV light exhibited a transistor operation under appropriate gate and drain bias voltages, meanwhile the open-ring isomer produced by VIS light showed no drain current. As a result, a remarkably high on/off ratio of 1,000 was achieved. The drain current modulation can be attributed to the drastic transformation in the π-conjugation system in association with the photo-isomerization. These results present two important messages. The first one is that this compound has dual properties: organic semiconductor and photochromism. The second is that a phase transition between semiconductor and insulator can be induced by light irradiation.

Based on these achievements, we demonstrate laser drawing of one-dimensional (1D) channels on an OFET with a photochromic DAE layer (See Fig.1). The main findings are: i) a number of 1D channels can be written and erased repeatedly in the DAE layer by scanning UV and VIS focused laser spots alternately between the source and drain electrodes, ii) the conductivity of the 1D channel can be controlled by the illumination conditions, and iii) it is possible to draw an analogue adder circuit by optically writing 1D channels so as to overlap a portion of the channels and perform optical summing operations by local laser illumination on the respective channels. These findings will open new possibilities of various optically reconfigurable low-dimensional organic transistor circuits, which are not possible with conventional thin film OFETs.

Speaker
Biography:

Bi-Hsuan Lin has completed his Ph.D. from Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan and postdoctoral studies from European Synchrotron Radiation Facility (ESRF) for one year. Now He works at National Synchrotron Radiation Research Center as the assistant research scientist. He is participating the construction and commission of the X-ray nanoprobe beamlime at Taiwan Photo Source (TPS), and is responsible for development of the XEOL and TR-XEOL.

Abstract:

The advantages of using synchrotron radiation as the excitation source are that the tunable X-ray energy allows the preferential excitation of the elements through the X-ray absorption edges, and a suitable time structure of the synchrotron can be used to study the dynamics of luminescence of the materials. We develop the synchrotron based hard X-ray excited optical luminescence (XEOL) and time-resolved X-ray excited optical luminescence (TR-XEOL) at the X-ray Nanoprobe (XNP) facility at Taiwan Photon Source (TPS). In parallel to the construction of the XNP endstation, demonstrative XEOL experiments were conducted  by unfocused X-ray beam at Taiwan Light Source (TLS). The low temperature (4.2K) and temperature-dependent XEOL with X-ray excited energy below, at and above the Zn K-edge (9.659keV) were used to obtain the further information of the optical mechanisms of the ZnO microwires. The temperature-dependent XEOL behavior of the ZnO microwires with X-ray energy at 9.67 keV was shown in Figure 1. The free A excitons, donor bound excitons and their phonon replicas can be seen unambiguously at low temperatures. The design of the XEOL and TR-XEOL at XNP and the demonstrative experimental results will be reported.

Speaker
Biography:

Sang-Wook Han published over 70 research papers in solid state physics, nanoscience, and nanotechnology and given over 30 invited lectures. His major research field is the micro-structural and chemical property characterizations of nanomaterials using X-ray absorption fine structure (XAFS) and nanomaterial applications including sensors, battery, and solar cells.

Abstract:

VO2 is a typical metal-insulator-transition(MIT) material with the bandgap of ~0.7 eV and the Tc of ~ 70oC. VO2 is transparent and dark below and above the Tc, so that it can be applicable for smart windows by controlling the temperature. VO2 nanoparticles in a metallic phase block and scatter sunlight. The scattered sunlight by VO2 nanoparticles can be used in solar cells. We examined the local structural and electrical properties from VO2/ ZnO nanostructures by using the simultaneous measurements of x-ray absorption fine structure(XAFS) and resistance. The structural and electrical properties of VO2 depend on the length of ZnO nanorods underneath VO2. Direct comparison of simultaneously-measured resistance and XAFS from the VO2 demonstrates that the transitions of structures, local density of the V 3d orbital states, and resistance occurred in sequence during heating, whereas the properties changed simultaneously during cooling. XAFS reveals a substantial increase of Debye-Waller factors, particularly, V-V pairs along the {111} direction in the metallic phase. XAFS results indicate that soft phonon above Tc plays a critical role in the collapse of a small band gap of VO2. The local structural and the electrical properties of VO2/ZnO nanorods are considerably sensitive to the interface of VO2/ZnO as well as the length of ZnO nanorods. The interface properties of VO2 hetero-structures of should be taken into account for its applications to smart windows and solar cells.

Speaker
Biography:

Mehdi Mehdi is a PhD candidate from the University of Windsor. His education includes a BSc (Hons) in Physics and Mathematics, a MASc in Physics and currently in his final year of PhD studies in Engineering Materials.  His research interests include corrosion science (Mg and Al alloys), tribology (Titanium alloys), soft magnetic materials (Si-Fe alloys), recrystallization phenomena and texture analysis. He is also interested in texture simulations, mathematical modeling and magnetic measurements using Barkhausen noise (MBN) and Epstein frame. He has been a researcher at Canmet Materials (Natural Resources Canada since 2015). His other interests include teaching engineering, physics and math. He has been doing that for the past 7years at the University of Windsor and with The Princeton Review. 

Abstract:

In order to enhance the magnetic properties of non-oriented electrical steel an unconventional cold rolling scheme was used in this study, in which the cold rolling was carried out at an angle (i.e. 22.5° and 45°) relative to the hot rolling direction (HRD), using both unidirectional feeding and bidirectional feeding. This cold rolling scheme has been shown to promote the magnetically favourable <001>//ND texture (the θ-fibre) and minimize the unfavourable <111>//ND (γ-fiber) and <110>//RD (α-fibre) components in our previous studies. Half of the cold rolled electrical steel samples were annealed at 750 °C for 1 hour, and the texture was measured using Electron Back Scatter Diffraction (EBSD). The effect of changing the cold rolling direction on the Barkhausen noise amplitude has been investigated for various magnetization directions and compared to conventional rolling. This characterization technique was employed on the as deformed electrical steels to investigate the dependence of Barkhausen noise amplitude on stress distribution resulting from the different cold rolling schemes. While, it was applied on the annealed samples to explore the effect of texture on the MBN. 
Keywords: Non-oriented electrical steel, texture, Barkhausen noise, annealing, EBSD, skew rolling.