Tag: STER

SPOTLIGHT TALK – 17/09/2024

The Warsaw Doctoral School in Natural and Biomedical Sciences and the Institute of Physics PAS cordially invites you to a SPOTLIGHT TALK.

The talk is given by Dr. Igor Reva (CERES, Department of Chemical Engineering, University of Coimbra, Portugal).

When and where?

17th August 2024, 10:30 am
at the IP PAS Leonard Sosnowski Auditorium, duration: 45 min + question time

Abstract

Studies on the photochemical reactivity and characterization of the primary photoproducts permit a deeper understanding of reaction mechanisms. In this talk, the experimental technique of low temperature matrix isolation allowing to experimentally test the incipient steps of photochemical reactions, and to characterize novel species with unusual functionalities, properties and behavior will be addressed.

We shall start with the fundamentals of the method and show its possibilities in the studies of structure and reactivity at cryogenic temperatures (~10 K). Typically, the molecules are embedded in solid inert matrices (Ar, Xe, N₂) and excited in situ either by a broadband light source, such as Hg/Xe lamp, or by narrowband light generated in an optical parametric oscillator or in a diode laser. The structures of reactants and photoproducts are characterized experimentally by infrared spectroscopy and theoretically by computation of vibrational spectra.

The potential of the method will be demonstrated using several conformational studies. Narrowband near-infrared irradiations, tuned at the frequencies of the OH or NH first overtone modes, result in conformational switching. Hereby, it becomes possible to characterize high-energy conformers, not accessible experimentally otherwise, and study processes of intramolecular vibrational energy transfer. The examples will include carboxylic acids, amino acids, nucleobase cytosine, among others. Besides, the isomerizations occurring in matrix-isolated molecules in dark (H-atom and heavy-atom tunneling) and those induced by the light source of the spectrometer will be discussed.

Further examples concern the reactivity induced by frequency-tunable UV light. Here, H-atom transfer reactions, resulting in oxo-hydroxy, amine-imino, thiol-thione isomerism, for phenol, cytosines, thiophenol, and some heterocycles will be described.

In general, this contribution will provide a selection of experimental and computational results, co-authored by the presenter, providing insight into the observed reactivity.

This event is supported by the Polish National Agency for Academic Exchange, grant no. BPI/STE/2021/1/00034/U/00001.

About the speaker

Igor Reva graduated in Biophysics, with honors, from the Kharkiv State University. Upon graduation, worked for several years as engineer, at the Institute for Low Temperature Physics & Engineering (ILTPE), a major research centre of the National Academy of Sciences of Ukraine (in Kharkiv), where he mastered diverse technical aspects of cryogenic applications.

In 1995, completed a PhD degree in Molecular Physics & Biophysics, at ILTPE.

In July 1997 – September 1999, Igor Reva was awarded a post-doctoral fellowship of the Alexander von Humboldt Foundation at Max-Planck-Institute (MPI) for Radiation Chemistry (Mülheim-an-der-Ruhr, Germany) and MPI for Nuclear Physics (Heidelberg, Germany).

Since October 1999 and until 2020, moved to the University of Coimbra (UC), Portugal, where he worked as: (i) post-doctoral fellow of the Portuguese “Fundação para a Ciência e a Tecnologia” (FCT), (ii) Researcher (FCT program “Science-2007”), (iii) Principal Researcher (program “Investigador FCT”), all above positions at the Centre of Chemistry of Coimbra, Department of Chemistry (DQ) at UC. Since 2021 (till present), Igor Reva works at the Research Centre hosted at the Department of Chemical Engineering (DEQ) at UC. Since 2024, this research centre at DEQ/UC is named CERES (from Portuguese: “Chemical Engineering and Renewable Resources for Sustainability”).

In 2010, the degree of Habilitation in Chemistry was conferred on Igor Reva by UC, with specialization in Molecular Spectroscopy.

The engineering skills and qualification, acquired by Igor Reva at ILTPE, allowed him subsequently to design and construct in Portugal (at DQ/UC) a home-made fully operational experimental setup for matrix-isolation spectroscopy and photochemistry at cryogenic temperatures. This setup is now an integrated part of Coimbra Laser Lab (CLL), hosted at DQ/UC. CLL is a Research Infrastructure of FCT established at UC and is a part of LaserLab Europe – Consortium of European Laser Research Infrastructures (35 organizations from 18 countries). At CLL, Igor Reva provided scientific supervision and technical training for users from +20 countries.

Main specializations of Igor Reva are infrared spectroscopy, photochemistry, photochromic molecules, molecular switches, reactive intermediates, systems with open electronic shells, quantum mechanical tunneling, including their experimental and computational studies.

He participated in +30 competitively funded FCT projects (in 8 as principal investigator). As of September 2024, published +170 articles in peer-reviewed journals, in 1/3 of these Igor Reva is the corresponding author. H-index: 42 (Publons) / 43 (Scopus), with +5 K citations.

Considering the present STER application to NAWA, it should be noted that Igor Reva participated in two bilateral projects with IF PAN, acting as coordinator for the Portuguese side. Each of these two projects lasted two years. Collaborations  with researchers from IF PAN resulted in 42 joint peer-reviewed publications.

SPOTLIGHT TALK – 14/08/2024

The Warsaw Doctoral School in Natural and Biomedical Sciences and the Institute of Physics PAS cordially invites you to a SPOTLIGHT TALK.

The talk is given by Prof. Jarah Evslin (Institute of Modern Physics, Chinese Academy of Sciences).

When and where?

14th August 2024, 10:30 am
at the IP PAS Auditorium, duration: 90 min + question time

Abstract

Solitons show up in many fields of physics from the monopoles and models of nucleons in strong interactions, to conducting plastics and novel memory storage devices. However, solitons are largely understood using classical physics. It is widely believed that quantum mechanics qualitatively changes some of their properties, for example causing some to quickly decay. We will describe a new method which allows for an efficient, reliable and complete treatment of solitons in quantum physics.

In the second lecture, we will describe some recent progress in constructing quantum kinks. We will describe how states, decay rates and scattering amplitudes may be found. Also we will introduce oscillons, which are thought to be the dominant degrees of freedom after violent events including some first order phase transitions and inflationary paradigms. We will describe how these new methods may be used to understand whether quantum corrections cause oscillons to decay so quickly that they are phenomenologically irrelevant.

This event is supported by the Polish National Agency for Academic Exchange, grant no. BPI/STE/2021/1/00034/U/00001.

About the speaker

Jarah Evslin got his Bachelor of Science degree in Math and Bachelor of Science degree in Physics from Caltech in 1997, he got his PhD degree in Physics from the University of California Berkeley in 2001. After that he did his postdocs in Pisa, Trieste and Brussels. Later he became an adjunct professor at the University of Pisa.

Since 2014, he is a professor at the Institute of Modern Physics, Chinese Academy of Sciences. He is the coordinator of the International Science Development Team for Fundamental Physics at the Thirty Meter Telescope. He published 112 papers in refereed journals, plus 1 book chapter and 7 proceedings. In the past, he has studied dark matter, dark energy, string theory, black holes and neutrino physics. For the past 5 years, his research has worked towards understanding why gluons and quarks are always confined in nuclei.

SPOTLIGHT TALK – 13/08/2024

The Warsaw Doctoral School in Natural and Biomedical Sciences and the Institute of Physics PAS cordially invites you to a SPOTLIGHT TALK.

The talk is given by Prof. Jarah Evslin (Institute of Modern Physics, Chinese Academy of Sciences).

When and where?

13th August 2024, 10:30 am
at the IP PAS Auditorium, duration: 90 min + question time

Abstract

Solitons show up in many fields of physics from the monopoles and models of nucleons in strong interactions, to conducting plastics and novel memory storage devices. However, solitons are largely understood using classical physics. It is widely believed that quantum mechanics qualitatively changes some of their properties, for example causing some to quickly decay. We will describe a new method which allows for an efficient, reliable and complete treatment of solitons in quantum physics.

In the first lecture, classical solitons will be introduced. We will give a brief introduction to different kinds of solitons: kinks, vortices, monopoles and domain walls. We will describe them using classical field theory and note some of their applications in classical and quantum physics.

This event is supported by the Polish National Agency for Academic Exchange, grant no. BPI/STE/2021/1/00034/U/00001.

About the speaker

Jarah Evslin got his Bachelor of Science degree in Math and Bachelor of Science degree in Physics from Caltech in 1997, he got his PhD degree in Physics from the University of California Berkeley in 2001. After that he did his postdocs in Pisa, Trieste and Brussels. Later he became an adjunct professor at the University of Pisa.

Since 2014, he is a professor at the Institute of Modern Physics, Chinese Academy of Sciences. He is the coordinator of the International Science Development Team for Fundamental Physics at the Thirty Meter Telescope. He published 112 papers in refereed journals, plus 1 book chapter and 7 proceedings. In the past, he has studied dark matter, dark energy, string theory, black holes and neutrino physics. For the past 5 years, his research has worked towards understanding why gluons and quarks are always confined in nuclei.

SPOTLIGHT TALK – 25/06/2024

The Warsaw Doctoral School in Natural and Biomedical Sciences and
the Institute of Physics PAS cordially invites you to a SPOTLIGHT TALK.

The talk is given by Dr. Sérgio Nuno Canteiro de Magalhães (IPFN, Instituto de Plasmas e Fusão Nuclear, Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 2695-066 Bobadela LRS, Portugal).

When and where?

25th June 2024, 10:30 am
at the IP PAS Auditorium, duration: 45 min + question time

Abstract

Recent progress in the growth techniques makes it possible to fabricate low-dimensional structures, e.g., thin films (planar multilayers), mesoscopic structures and nanostructures (lateral surface and multilayer gratings, quantum wires and dots). The opto- and micro-electronics are among the fields where the resulting novel properties of homo(hetero)-epitaxial growth of semiconductors are more significant. The optimization of the fabrication process and the physical understanding of the samples requires non-destructive structural studies of the materials. Improving the properties of the as-grown quantum materials is also fundamental from the point of view of the Nanotechnology. An example of controlled process to change the properties of materials is the ex-situ incorporation of ion species. The possibility to control dopant concentrations, depth profiling and the high purity through mass selection turn ion implantation into a silicon industry ready-to-use tool. However, the stochastic nature of the process in which energetic ions collide and penetrate the semiconductor, results in lattice damage. Although the crystal degradation is partially reversed after thermal or pressure annealing’s, vacancies and point defects introduced and rearranged after annealing create a strain field which does not disappear completely. Complementary to the direct local probing methods (atomic force microscopy, transmission electron microscopy (TEM), high angle annular dark field (HAADF) or phase analysis to determine the strain in quantum materials), the X-ray elastic scattering methods probe locally the reciprocal space, thus providing relevant information about the statistical properties of the structural parameters averaged over a large volume of a sample. X-ray diffraction (XRD) and reflectivity (XRR) in the specular and non-specular geometries are relevant techniques for these structural studies of both crystalline and amorphous systems. They are highly sensitive to the distribution of the lattice parameters (diffraction) and refractive index (reflectivity). This presentation explores the synergy between ion beam implantation and X-ray scattering techniques to advance the understanding of implanted crystalline materials. Several examples of implanted single and polycrystalline crystals will be presented following by an overview of the required theoretical principles underlying both techniques. To predict the decrease of the crystalline induced by the ion implantation, a new approach to the interpretation of the diffraction data of implanted crystals will be presented. The novel methodology considers the effects of the variations of the atom’s positions in the lattice instead of employing the static Debye-Waller, strictly related to thermal vibrations. The new method, supported by preliminary molecular dynamics simulations, is tentatively applied to chromium implanted Ga₂O₃ and carbon implanted 4H-SiC bulk-crystals and to argon implanted GaN thick layers grown by MOCVD on sapphire-c substrates. Finally, a brief description of the MROX software, acronym for Multiple Reflection Optimization package for X-ray scattering used to simulate the XRD data, is highlighted.

This event is supported by the Polish National Agency for Academic Exchange,
grant no.  BPI/STE/2021/1/00034/U/00001.

About the speaker

Sérgio Nuno Canteiro de Magalhães (ORCID number: 0000-0002-5858-549X; Web of Science ResearcherID: A-6709-2018) is a DL57 researcher under the 16/IPFN contract at Instituto Superior Técnico in Lisbon, Portugal. This contract was awarded for the development of models aimed at studying the effects of ion-implanted nano-materials using X-rays and ion beams.

Sérgio Magalhães’s journey into the realm of crystal growth began with the exploration of recent advancements in techniques, which have revolutionized the creation of low-dimensional structures. These structures, encompassing thin films, mesoscopic forms, and nanostructures, hold immense significance for Condensed Matter Physics, particularly in opto- and micro-electronics. Their uniqueness stems from the epitaxial growth of semiconductors, facilitated by cutting-edge crystal growth methods.

Sérgio Magalhães’s fascination with enhancing the attributes of these materials led to delve into the realm of Nuclear Sciences. Here, Sérgio Magalhães discovered the pivotal role of controlled processes in modifying materials, particularly through ex-situ incorporation of ion species. This method allows for precise manipulation of dopant concentrations, depth-profiling, and ensuring high purity through mass selection, thereby positioning ion implantation as a key tool for integration into the silicon industry. However, the journey is not without its challenges. On the on hand, the stochastic nature of ion implantation brings forth lattice damage as energetic ions interact and penetrate the semiconductor lattice. While thermal or pressure annealing offers partial relief, the introduction of vacancies and point defects during this process leaves behind residual strain fields that persist beyond annealing. On the other hand, the advanced measurements acquired from X-ray scattering and ion beam techniques demand equally sophisticated computer software tools to simulate their data. In response to this need, the MROX (Multiple Reflection Optimization) package for X-ray diffraction/reflection software has been recently developed. It should be emphasized that program made by Sérgio Magalhães allows to simulate XRD data of advanced semiconductor structure systems (superlattices, nanowires, quantum-dots, thin layers, ion implanted structures) what is impossible in commercial available XRD software. Already, MROX program has been credited in 16 research manuscripts published in reputable international peer-reviewed journals. Driven by the quest to unravel these complexities and enhance material properties, Sérgio Magalhães embarked on a mission to conduct non-destructive structural investigations. Leveraging X-ray and ion beam techniques, Sérgio Magalhães’s goals are to gain deeper insights into the mechanisms of damage accumulation in crystals. The success has been bolstered by over 60 research publications, facilitated by numerous international collaborations, including partnerships with esteemed institutions such as the Institute of Physics at the Polish Academy of Sciences.

SPOTLIGHT TALK – 19/06/2024

The Warsaw Doctoral School in Natural and Biomedical Sciences and the Institute of High Pressure Physics PAS cordially invites you to a SPOTLIGHT TALK.

The talk is given by Dr. Cecilia Mortalo (Consiglio Nazionale delle Ricerche – Instituto di Chemica della Materia Condensata e di Technologie per l’Energia (CNR-ICMATE), Corso Stati Uniti 4, 35127 Padova, Italy).

When and where?

19th June 2024 2024, 12:30 pm
at the IHPP PAS New Technologies Building, Al. Prymasa Tysiąclecia 98 Duration: 60 min + more

Abstract

Hydrogen separation and purification technology is a key element in the use of H2 as an energy carrier and in other important technological applications. Dense ceramic materials based on mixed ionic and electronic conductors (MIEC) are currently attracting growing interest for their potential application in H2 separation membranes or in catalytic membrane reactors at T > 600°C. Indeed, these membranes allow a selective non-galvanic separation by incorporating H2 in their crystal structure as charged protonic defects and electrons/holes that are transported to the opposite side of the membrane under an H2 partial pressure gradient, i.e. without any external energy. When used as membrane reactors, they also combine separation and reaction in a single unit, increasing efficiency.

In this context, ceramic-ceramic (cer-cer) composites have gained interest in the last 5 years due to their improved hydrogen permeability compared to single phase materials. Among these, dual-phase membranes based on ceria zirconate perovskites and doped ceria oxides have demonstrated remarkable performance as dense H2-separation membranes, with H2 flux values among the highest reported in the literature for this type of system.

The seminar will provide a comprehensive overview of the use of proton conducting ceramic membranes for hydrogen separation, with particular emphasis on dual-phase ceramic membranes based on BaCe0.65Zr0.20Y0.15O3-δ (BCZ20Y15) perowskite and doped ceria (Ce0.85M0.15O2-δ M = Y or Gd, YDC15 or GDC15) composites. The preparation methods, hydrogen permeability and chemical stability issues are also discussed.

CANCELLED! SPOTLIGHT TALK – 10/06/2024

The Warsaw Doctoral School in Natural and Biomedical Sciences and the Institute of High Pressure Physics PAS cordially invites you to a SPOTLIGHT TALK.

The talk is given by Prof. Horst Hahn (Sustainable Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, OK, United States of America; Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Germany).

When and where?

10th June 2024 2024, 12:30 pm – CANCELLED
at the IHPP PAS New Technologies Building, Al. Prymasa Tysiąclecia 98 Duration: 60 min + more

Abstract

Advanced materials are typically characterized by complex nano- and microstructures with various phase compositions, grain sizes, chemical inhomogeneity or homogeneity, crystalline and amorphous structures, all leading to metastability. Over the past 30 years, many new materials have been developed making use of these possibilities and leading to many interesting properties. Prominent examples of such materials are metallic glasses, nanocrystalline materials and high entropy materials. In recent years, new ideas and novel synthesis routes have shown the way to advanced materials with yet unknown structures and properties. The talk will present examples of synthesis, characterization and properties of advanced materials with amorphous and crystalline structures: nanoglasses, cluster-assembled amorphous and crystalline materials and high entropy oxides.

SPOTLIGHT TALK – 21/05/2024

The Warsaw Doctoral School in Natural and Biomedical Sciences and the Institute of High Pressure Physics PAS cordially invites you to a SPOTLIGHT TALK.

The talk is given by Dr. Andriy Palasyuk (Critical Materials Institute, Ames Laboratory, USA).

When and where?

21st May 2024, 11:00 am
at the IHPP PAS New Technologies Building, Al. Prymasa Tysiąclecia 98, seminar room, 2^nd floor
Duration: 60 min + more

Abstract

A gap in the market exists between super strong neodymium magnets and less sensitive ferrite magnets. This gap means that compromises are made in engineering items like car sensors or wind turbine rotors. The Critical Materials Institute is working on a cerium-based magnet that will hit the sweet spot between powerful rare earth magnets and the much weaker ferrites. The magnet is process effective and less susceptible to supply chain disruptions. Its unique intra-granular coercivity mechanism does not require complicated microstructure developments and opens potential for advanced manufacturing.

SPOTLIGHT TALK – 08/05/2024

The Warsaw Doctoral School in Natural and Biomedical Sciences and the Institute of High Pressure Physics PAS cordially invites you to a SPOTLIGHT TALK.

The talk is given by Prof. Eugen Rabkin (Department of Materials Science and Engineering, Technion – Israel Institute of Technology, 3200003 Haifa, Israel).

When and where?

8th May 2024 2024, 12:30 pm
at the IHPP PAS New Technologies Building, Al. Prymasa Tysiąclecia 98 Duration: 60 min + more

Abstract

We studied the uniaxial compression behavior of micro- and nanoparticles of several elemental metals (Au, Ni, Ag, Mo, Pt) and alloys (Ni-Co, Ni-Fe, Au-Ag, Cu-Au). The particles were obtained by solid state dewetting of thin metal films and bi-layers deposited on sapphire substrates. The high homological temperatures employed in dewetting process ensure the low concentration of dislocations and their sources in the particles. The particles compressed with a flat diamond punch exhibit purely elastic behavior up to very high values of strain approaching 10%, followed by a catastrophic plastic collapse. The uniaxial yield strength of the particles defined as an engineering stress at the point of catastrophic collapse reached the astonishing values of 34, 41 and 46 GPa for the smallest faceted particles of Ni, disordered Cu₃Au, and Mo, respectively. The atomistic molecular dynamic simulations of the particle compression demonstrated that the catastrophic plastic yielding of the particles is associated with the multiple nucleation of dislocations at the facet corners or inside the particles. The latter, homogeneous nucleation mode resulted in higher particle strength. The size effect in compression was observed both in the experiments and in atomistic simulations, with smaller particles exhibiting higher compressive strength. We discussed the stronger size effect observed in the experiment (as compared with simulations) in terms of the effect of residual defects trapped in the particles. Finally, we produced Au-Ag core-shell nanoparticles by coating the single crystalline Ag nanoparticles with a polycrystalline Au shell. The core-shell nanoparticles exhibited much lower strength than their single crystalline pure Ag counterparts. We related this decrease in strength with the active role of grain- and interphase boundaries in the polycrystalline Au shell in decreasing the energy barrier for dislocations nucleation.

SPOTLIGHT TALK – 26/04/2024

The Warsaw Doctoral School in Natural and Biomedical Sciences and the Institute of Organic Chemistry PAS cordially invites you to a SPOTLIGHT TALK.

The talk is given by Prof. Herre van der Zant (Kavli Institute of Nanoscience, Delft University of Technology, Netherlands).

When and where?

On Friday, 26th April 2024 at 10 a.m.
Aula IOC/ICP PAS, Warsaw, Kasprzaka 44/52

This event is supported by the Polish National Agency for Academic Exchange, grant no. BPI/STE/2021/1/00034/U/00001.