The Field-of-Expertise Advanced Materials Science is an interdisciplinary network of researchers at the TU Graz in chemistry, physics, architecture, mechanical engineering, civil engineering, electrical engineering and geodesy who discover, characterize and model materials, functional coatings and components. Thirty-one institutes from six faculties are presently involved.
Advanced Materials Day is the yearly meeting where the members of the FOE present their latest results. In 2018, the meeting will be held on September 21 at the Neue Technik campus in the Biomedical Technology building.
|09:00 - 09:10|
09:10 - 09:30
Real-time tracking of electron and spin dynamics
Abstract: By means of attosecond spectroscopy we can explore electron and spin dynamics in real time. This information can be crucial to understand the microscopic origin of a functional material’s interaction with light. As examples I will show how quickly silicon can absorb a photon and introduce an experiment that recorded the fastest magnetic switching ever achieved.
|09:30 - 09:50|
Porous Materials @ Work
|09:50 - 10:10|
Design of sustainable hybrid electrochemical capacitors
Abstract: Hybrid electrochemical capacitors display higher power than batteries and higher energy than electrical double-layer capacitors (EDLCs). Generally, in these devices, high surface area activated carbon is used as electrode materials. To enhance energy, we have implemented redox active aqueous electrolyte which transforms the charging mechanism of positive electrode to a battery-like, and it is then internally hybridized with an electrical double-layer (EDL) negative electrode. Thereby, a hybrid cell displays twice higher capacitance than its symmetric counterpart. This construction is advantageous owing to the low assembling cost, no toxicity issues and high cycling performance. The presentation will include data related with investigation of carbon/redox specie interface by thermogravimetry coupled with mass spectrometry (TG-MS) and Raman spectroscopy.
10:10 - 10:30
Studies of ionizing radiation effects in nanoscale CMOS technology nodes
Abstract: X-ray radiation damage of semiconductor devices originates from radiation-induced fixed charge in the insulating regions and interface traps . Device arrays fabricated in 28 nm bulk CMOS with pMOSFET and nMOSFET transistors of different dimensions have been studied. Stress tests have been performed with X-rays of energies in range 10 to 40 keV. Transfer and output characteristics have been measured before irradiation as well as after 12 steps of total ionizing dose (TID) to track evolution of device parameters. These steps start with 100 krad and 500 krad, corresponding to TID levels close to those experienced by instruments in space missions or medical imaging and reach ultrahigh levels of 900 Mrad, which is of interest for high energy physics experiments. Similarly to older technology nodes the effect of radiation induced narrow channel effect (RINCE)  related to traps within the shallow trench isolation (STI) is observed on device characteristics. Transistors in the 28 nm process, in contrast to technology nodes down to 65 nm already widely studied for TID effects, are equipped with high-K/metal gate. Therefore material properties and formation of traps might have to be reconsidered when interpreting the post-irradiation measurement results. TCAD device model including HfO2 - SiO2 gate stack and strained channel is adapted to measurement results. In this talk the 28nm CMOS process will be introduced and selected device parameters will be analysed with respect to radiation damage. Finally the approach of employing the model to examine various radiation damage effects observed after TID stress will be discussed.
|10:30 - 11:00|
|11:00 - 11:20|
Silica-based nanostructured particles/ SOMAPP Lab
Abstract: Lipid based liquid crystalline systems form various structures depending on the lipid composition, their hydrophilic head group as well as their lipophilic tail. These self-assembled structures formed are affected by temperature and additives[1–4]. Additionally, they can also be dispersed to form nanostructured particles.
|11:20 - 11:40|
Formation processes of dolomite at low temperature
Abstract: Dolomite is a Ca-Mg-carbonate mineral that is abundant in ancient carbonate platforms and is an important component of petroleum reservoir rocks. In its ideal state dolomite has the stoichiometric composition CaMg(CO3)2 (i.e. molar Ca:Mg = 1:1) and consists of an ordered arrangement of alternating layers of Ca2+ and Mg2+ cations interspersed with CO32- anion layers normal to the c-axis. The formation conditions of dolomite are not clearly understood as so far dolomite synthesis from an aqueous fluid under laboratory conditions and at ambient temperatures has not been established. Recent synthesis experiments at >140°C indicate that dolomite forms through a series of intermediate phases starting with an amorphous calcium magnesium carbonate (ACMC) precursor being replaced by very high Mg-calcite (VHMC). The VHMC products are subsequently replaced by a stoichiometric dolomite. However, a large gap of knowledge exists with respect to this reaction pathway at low temperature.
|11:40 - 12:00|
Eduardo Machado Charry
|12:00 - 12:20|
Posters 15:30 - 17:30
Influence of Molecule Size on Surface Polymorph Formation
Auxiliary master equation approach to the single-impurity Anderson model out of equilibrium
Thermomechanical Simulations of Microelectronics Packaging
Describing complex intramolecular interactions with Bayesian Learning: Pushing the Feature Vector to the limit
Raman microscopy of inorganic materials – A stone is a stone! Is a stone?
Abstract: “In our current laboratory exercise research project we are investigating the composition of common inorganic materials (such as rocks, dirt, crystals, and building materials) and the microscopic imaging of their components. A selection of samples from interested hobby geologist will be available, but students are also encouraged to bring their own samples (anything you are interested in from the soil in your back yard, to a weird looking rock you found while hiking). Our goal is to demonstrate that even in the limited time available during a lab exercise it is possible to produce a good quality analysis of a complex real world sample.”
Feature Selection for Functional Properties: Predicting Surface Rearrangements
Smart-Data Machine Learning for Surface Polymorph Prediction
Abstract: In this contribution we introduce the SAMPLE approach[1,2], a structure search tool for commensurate organic monolayers on inorganic substrates. The major challenge hereby is the large number of possible polymorphs such monolayers can form. To overcome this challenge, SAMPLE employs physically motivated coarse-grained modeling in combination with Bayesian linear regression to efficiently explore the potential energy surface.
Simulating Charge Transport Through Metal-Organic Semiconductor Interfaces: Bulk or Contact Limited?
Abstract: The performance of organic electronic devices crucially relies on an efficient charge injection. This efficiency is governed by a complex interplay of experimentally tunable properties like level alignment and disorder. The impact of this interplay on the bulk current is only poorly understood from a theoretical point of view. To overcome this lack of knowledge, we utilize mesoscopic simulations to predict the current density across the contact interface. In these simulations, charges are viewed to migrate through disordered organic semiconductors due to hopping between localised states. Parameters like injection barrier, energetic disorder, electric field, Coulomb interactions and temperature can be directly considered. This intuitive method holds the promise to understand the effects and interactions that govern the interplay between interfacial and bulk properties. We analyse the current density for instructive combinations of interface and bulk properties. This analysis yields two distinct regimes, a bulk limited regime and a contact limited regime. The evolution of the current density with respect to injection barrier, energetic disorder and electric field strength is investigated and the origin of bulk vs. contact limitation is analysed.
On the unexpected behaviour of Ni-Au and Co-Au core-shell nanoparticles
Abstract: We present molecular dynamics simulations, static basin hopping calculations as well as comparisons with transmission electron microscopy (TEM) studies of 5 nm Ni-Au and Co-Au core-shell particles upon heating. The bimetallic nanoparticles are monitored through a heating cycle up to 1300 K and their structural rearrangement is observed. Via static basin hopping calculations we show that decentralised cores represent for both model systems the energetically most stable configuration. Heating can trigger a rearrangement of an initially centralised cores, however, as temperature increases entropy becomes more dominant, which finally can result in an alloying of the cluster. We show that this fascinating behaviour is an interplay between atomistic and bulk characteristics deduced from surface size effects and bimetallic phase diagrams.
Three-dimensional geometric integrator for charged particle orbits in toroidal fusion devices
Abstract: A three-dimensional integrator for guiding center orbits of charged particles in toroidal fusion devices with 3D field geometry is described. The integrator uses a representation of the electro- magnetic field by low order polynomials on a 3D tetrahedal grid and is intrinsically designed to preserve the total energy, perpendicular adiabatic invariant, and the phase space volume accu- rately for any grid size. Thus, it belongs to the class of geometric integrators.
Simulating the Oxidation of AlGaAs in Semiconductor Devices
Towards new plasmonic materials: Synthesis of K and K-Au nanoparticles with helium droplets
Abstract: We report on experiments on K and bimetallic K-Au nanoparticles produced under UHV conditions by synthesis in helium nanodroplets. Bimetallic K-Au nanoparticles are promising candidates as building blocks for future meta-materials due to their excellent plasmonic properties. Considering the growing importance of plasmonic technology with diverse applications, for example, in photovoltaics, medical diagnostics, catalysis and surface enhanced Raman spectroscopy, the search for better plasmonic materials constitutes an important task for both science and industry.
Development of site-specific arrays of pressure, temperature and humidity multi-responsive nanorods
Understanding Phonon Properties in Metal-Organic Frameworks From First Principles
Surface Crystallization Studies of 2-decyl-7-phenyl-benzothieno[3,2-b]benzothiophene (Ph-BTBT-10)