Scientific Program

Conference Series Ltd invites all the participants across the globe to attend 5th International Conference on Theoretical, Materials and Condensed Matter Physics Los Angeles, USA.

Day 2 :

OMICS International Condensed Matter Physics 2018 International Conference Keynote Speaker Yutaka Ohno photo
Biography:

Yutaka Ohno (PhD: Physics) is working in the Institute for Materials Research, Tohoku University (http://www-lab.imr.tohoku.ac.jp/~yutakaohno/). He is also working in the CREST research project (Grant No. JPMJCR17J1 (2017-2023)) in Japan Science and Technology Agency. A focus is on quantitative analyses of the impurity segregation ability of grain boundaries in Si and compounds by atom probe tomography (APT, with a spatial resolution less than 0.4nm) combined with scanning transmission electron microscopy (STEM) and ab initio calculations, but also on the study of atomistic structures of semiconductor nanostructures by optical measurements (cathodoluminescence, micro-photoluminescence, near-field optical measurements) under TEM.

Abstract:

Polycrystalline materials with grain boundaries (GBs), involving excess free energy because of their structural imperfection, can reduce their energy by the nanoscopic structural changes of the GBs via impurity segregation. Those local changes at GBs can stabilize non-equilibrium nanostructures, resulting in the drastic change in the macroscopic properties of those materials. The mechanism of GB segregation is, however, far from being understood due to difficulties in characterizing both crystallographic and chemical properties of the same GB at atomistic levels. We have therefore developed an analytical method to determine the impurity segregation ability on the same GB at the same nanoscopic location by a joint use of atom probe tomography (APT) and scanning transmission electron microscopy (STEM) combined with ab initio calculations, and discussed the segregation mechanism at atomistic levels. Three-dimensional distribution of impurity atoms was systematically determined at the typical large-angle GBs, small-angle GBs, and dislocations on GBs in Si by APT with a high spatial resolution (about 0.4nm), and it was correlated with the atomic stresses around the GBs estimated by ab initio calculations based on atomic-resolution STEM data. It was shown that impurity atoms preferentially segregated at the atomic positions under specific stresses so as to attain a more stable bonding network by reducing the local stresses. For example, the number of segregating oxygen atoms per unit GB area (NGB) is proportional to both the number of the stressed positions per unit GB area (nbc) and the average concentration of oxygen atoms around the GB ([Oi ]) with NGB ~ 50nbc[Oi ].

Keynote Forum

Yuko Ichiyanagi

Yokohama National University, Japan

Keynote: Characterization of ferrite nanoparticles and application for theranostics
OMICS International Condensed Matter Physics 2018 International Conference Keynote Speaker Yuko Ichiyanagi photo
Biography:

Yuko Ichiyanagi is an Associate Professor at Yokohama National University since 2009 (Applied Physics) and Osaka University since 2017. She was invited and chaired at several international conferences. Now she has published more than 50 papers and books. has been serving as an International Advisory Committee Member of some reputed conferences.

Abstract:

Magnetic nanoparticles have drawn attention recently due to their interesting nanoscopic features and potential applications for not only recording electric materials but also in the biomedical field. Previously, we obtained monodispersive magnetic nanoparticles (MNPs) by an original wet chemical method and reported magnetic, structural and thermal properties. Local structure analysis by X-ray absorption fine structure (XAFS) was useful to estimate nanoscale materials. We also suggested some biomedical applications using MNPs after functionalization. These functional MNPs were further introduced into cells. Furthermore, cancer cell selective MNPs were developed. Based on these techniques, we proposed a therapeutic method of magnetic hyperthermia. Now we propose “theranostics” by development nanoparticles for diagnostic and therapeutic materials simultaneously. For the therapeutic part, several kinds of ferrite NPs were prepared and AC magnetic measurements were performed. The relationship between the imaginary part of magnetic susceptibility χ” and the increase in temperature in the AC field was estimated. We have carried out in vitro experiments using cultured human breast cancer cells, and a drastic hyperthermia effect was observed. As one of the diagnostic method, mass spectrometric imaging (MSI) was proposed. With this method, the targeting analyte can be detected only with the nanoparticles as matrices, and simultaneously we can see the distribution of the materials by mapping the spectra. By means of our matrices, targeting analyte of very low molecular weight was successfully detected. Furthermore, effective parameters for MRI contrast agent, signals of the third harmonic components for magnetic particle imaging (MPI) were observed.

OMICS International Condensed Matter Physics 2018 International Conference Keynote Speaker Taro Toyoda photo
Biography:

Taro Toyoda has completed his DSc from Tokyo Metropolitan University and Assistant Research Officer at National Research Council of Canada. After working at Fuji Electric Company and Nippon Mining Company, he was appointed as a Professor of The University of Electro-Communications. His research focuses on basic studies of optical properties in semiconductor quantum dots including photoexcited carrier dynamics and their applications to photovoltaic quantum dot solar cells. He has published more than 200 papers in reputed journals.

Abstract:

The present study focuses on the effect of the substrate surfaces with different crystal orientations on optical absorption and ground state energy in a system comprising CdSe quantum dots (QDs) adsorbed on (001) and (102) surfaces of anataseTiO2 (A-TiO2 ). We applied photoacoustic (PA) spectroscopy based on the photothermal phenomenon to characterize the optical absorption, not only in the bandgap absorption but in the sub-bandgap region owing to high sensitivity. Photoelectron yield (PY) spectroscopy is useful for determining the absolute ground state energy level of QDs. Adsorption time dependence by absorbance measurements shows that (1) the adsorption rate of CdSe QDs on A-TiO2 (001) is higher than that of A-TiO2 (102) in agreement with our DFT calculations ((001) >> (101) > (102)), and (2) the diameter increasing rate of CdSe QDs on A-TiO2 (102) is higher than that of A-TiO2 (001), indicating the anisotropic crystal growth. The ground state energy levels of CdSe QDs on A-TiO2 (102) are deeper than those on A-TiO2 (001), suggesting the impossibility of the sensitization from the excited state of CdSe QDs to the conduction band of A-TiO2 (102). Deeper value of the ground state energy level of CdSe QDs on A-TiO2 (102) than those on A-TiO2 (001) is the possibility due to the difference of the permittivity of A-TiO2 (001) and A-TiO2 (102).

OMICS International Condensed Matter Physics 2018 International Conference Keynote Speaker Rita John photo
Biography:

Rita John is Professor and Head, Department of Theoretical Physics, University of Madras, Chennai, India. She is Visiting Professor on Fulbright Fellowship at the Department of Physics and Astronomy, Texas Christian University, Fort Worth, Texas, USA (2014). Her area of research includes Computational/Theoretical Condensed Matter Physics. She has published over 50 papers in peer-reviewed journals. The book titled ‘Solid State Physics’ authored by her and published by Tata McGraw Hill publisher (2014) is used by Physics graduate students globally. She has edited and published 4 other books on advanced topics in Physics. She has also authored a book titled ‘Science uncovers the signature of God’ highlighting the scientific facts recorded in the Holy Bible. She is the recipient of various awards and prizes for her academic contributions.

Abstract:

Heusler alloys are intermetallic compounds made up of four interpenetrating fcc sublattices. Some of them have multifunctional nature i.e. a combination of functions (properties) within the same compound, which have technological applications. Co-based Heusler compounds gained considerable attention in the recent past due to their high Curie temperature, high spin polarization and tunable electronic structure with possible applications in spintronics. They have the general composition X2 YZ where X and Y are transition metals and Z is an sp element. Quaternary Heusler alloys (QHA) are formed when one of the X atoms is replaced by a third transition metal. In this study, the structural, electronic, magnetic and transport properties of CoFeNbZ (Z=Al, Si and In) quaternary Heusler compounds are investigated employing the full potential linearized augmented plane wave (FP-LAPW) method implemented in WIEN2k code within the density functional theory prescription. The exchange and correlation effects are treated by using generalized gradient approximation (GGA). From the electronic and magnetic properties, it is found that CoFeNbAl is a half-metal with a spin flip gap of 0.33 eV and satisfies the Mt =Zt –24 Slater Pauling rule. It is known that GGA underestimates the band gaps of semiconductors and insulators. Here, the Tran and Blaha modified Becke Johnson potential (TB-mBJ) is used to obtain accurate band gaps. The spin-flip gap increases to 0.34 eV with the use of TB-mBJ and the nature of gap changes from indirect to direct. The half-metallic gap in CoFeNbAl arises due to the complex hybridization between the d-states of transition metals Co, Fe, and Nb. CoFeNbIn has metallic behavior in both spin channels. CoFeNbSi is a near half-metal with a near integer magnetic moment. The effect of hydrostatic strain on the magnetic and half-metallic properties of CoFeNbAl is determined. The transport coefficients such as the Seebeck coefficient, electrical conductivity, and thermal conductivity are computed in combination with the second principles BoltzTraP code. In the spin-up channel, electrical conductivity decreases as a function of temperature whereas it increases in the spin down the channel for CoFeNbAl. This affirms the metallic behavior in the spin-up channel and the semiconducting behavior in the spin down channel. The high spin polarization and robustness of half-metallicity against hydrostatic strain make CoFeNbAl a potential candidate for spintronic applications.

Keynote Forum

Feroz Alam Khan

Bangladesh University of Engineering and Technology, Bangladesh

Keynote: Influence of Mn substitution on magnetoresistance and magnetic properties of (Fe1-xMnx ) 75P15C10 alloy ribbons
OMICS International Condensed Matter Physics 2018 International Conference Keynote Speaker Feroz Alam Khan photo
Biography:

Feroz Alam Khan has completed his PhD degree from the Bangladesh University of Engineering and Technology (BUET) and his Postdoctoral Research at the University of Delaware, USA, University of Uppsala, Sweden, and the University of Tsukuba, Japan. He is a Professor in Physics at the Bangladesh University of Engineering and Technology (BUET). He is a leader of a research group called Dhaka Materials Science Group under a scientific research collaboration with the International Science Programs (ISP), Uppsala University, Sweden. He has supervised more than 25 postgraduate degrees that include Masters, MPhil, and PhD degrees. He has to his credit more than 50 research publications. He is involved in promoting basic science research through the establishment of regional research collaborations with the south-east Asian Universities under the umbrella of International Science Programs.

Abstract:

Magnetic properties have been measured on a rapidly cooled melt spun (Fe1-xMnx )75P15C10 (x=0, 0.05, 0.1, 0.2 and 0.3) amorphous alloys ribbons. The amorphous property of the ribbons have been confirmed by X-ray diffraction and scanning electron microscopy analysis. The observed magnetic properties e.g. magnetization and magnetoresistance and the ac permeability indicate that (Fe1-xMnx )75P15C10 goes through a transition from the ferromagnetic to antiferromagnetic-like phase within the temperature range of observation. Both positive and negative magnetoresistance have been observed at room temperature for different electrical circuital configurations as a function of the applied magnetic field. Saturation magnetization (Ms ) and the low field coercivity (Hc ) at room temperature indicates the magnetic softness of the alloy. The temperature dependent ac permeability shows high effective permeability at room temperature and shows a permeability minima around 450K. The ac permeability shows a maximum around 1kHz and diminishes at the high-frequency regime. The magnetoresistance of all the samples goes through a minimum around 4kOe showing a spin-valve type behavior which may be attributed to the suppression of quantum localization of the spin moments.