1. Measuring Thermal Diffusivity of Azoheteroarene Thin Layers by Photothermal Beam Deflection and Photothermal Lens MethodsAmeneh Mikaeeli, Dorota Koret, Humberto Cabrera, Dariusz Chomicki, Dariusz Dziczek, Oksana Kharchenko, Peng Song, Junyan Liu, Andreas D. Wieck, Michal Pawlak, 2023, izvirni znanstveni članek Ključne besede: thin films, photothermal spectroscopy, thermal transport, thermal wave, thermal conductivity, thermal diffusivity
Objavljeno v RUNG: 21.09.2023; Ogledov: 57; Prenosov: 0
 Celotno besedilo (882,88 KB) |
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4. Voltage-Dependent FTIR and 2D Infrared Spectroscopies within the Electric Double Layer Using a Plasmonic and Conductive ElectrodeNan Yang, Matthew J. Ryan, Minjung Song, Andraž Mavrič, Martin T. Zanni, 2023, izvirni znanstveni članek Opis: Strong electric fields exist between the electric double layer and charged surfaces. These fields impact molecular structures and chemistry at interfaces. We have developed a transparent electrode with infrared plasmonic enhancement sufficient to measure FTIR and two-dimensional infrared spectra at submonolayer coverages on the surface to which a voltage can be applied. Our device consists of an infrared transparent substrate, a 10–20 nm layer of conductive indium tin oxide (ITO), an electrically resistive layer of 3–5 nm Al2O3, and a 3 nm layer of nonconductive plasmonic gold. The materials and thicknesses are set to maximize the surface number density of the monolayer molecules, electrical conductivity, and plasmonic enhancement while minimizing background signals and avoiding Fano line shape distortions. The design was optimized by iteratively characterizing the material roughness and thickness with atomic force microscopy and electron microscopy and by monitoring the plasmon resonance enhancement with spectroscopy. The design is robust to repeated fabrication. This new electrode is tested on nitrile functional groups using a monolayer of 4-mercaptobenzonitrile as well as on CO and CC stretching modes using 4-mercaptobenzoic acid methyl ester. A voltage-dependent Stark shift is observed on both monolayers. We also observe that the transition dipole strength of the CN mode scales linearly with the applied voltage, providing a second way of measuring the surface electric field strength. We anticipate that this cell will enable many new voltage-dependent infrared experiments under applied voltages.
Ključne besede: two-dimensional infrared spectroscopy, infrared transparent substrate, voltage-dependent infrared experiments
Objavljeno v RUNG: 24.02.2023; Ogledov: 541; Prenosov: 0
Celotno besedilo (6,07 MB) |
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6. Electronic and chemical surface properties of Bi2Se3 derived compoundsZipporah Rini Benher, doktorska disertacija Ključne besede: Bismuth selenide derived compounds, surface chemical and electronic properties, topological insulators, single crystals, phase separation, inorganic bulk heterostructures, ix
Bridgman method, X-ray powder diffraction, scanning electron microscopy, photoelectron spectroscopy
Objavljeno v RUNG: 16.12.2022; Ogledov: 747; Prenosov: 11
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8. V-ORAL17c: Cationic Covalent Organic Polymer for Bacterial Cell Detection by Electrochemical Impedance SpectroscopyTina Skorjanc, Andraz Mavric, Mads Nybo Sorensen, Gregor Mali, Changzhu Wu, Matjaz Valant, 2022, objavljeni znanstveni prispevek na konferenci Ključne besede: Electrochemical impedance spectroscopy, polymers, Menshutkin reaction, porphyrin, sensor
Objavljeno v RUNG: 30.11.2022; Ogledov: 584; Prenosov: 0
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9. Photopyroelectric spectroscopy and calorimetryD Dadarlat, C Tripon, IR White, D Korte, 2022, pregledni znanstveni članek Opis: In this tutorial, we present an overview of the development of the photopyroelectric (PPE) technique, from its beginnings in 1984, through to the present day. The tutorial is organized in five sections, exploring both theoretical and experimental aspects of PPE detection, as well as some important spectroscopic and calorimetric applications. In the “Introduction” section we present the fundamental basics of photothermal phenomena and the state-of-the-art of the photopyroelectric technique. In the “Theoretical aspects” section we describe some specific cases of experimental interest, with examples in both back and front detection configurations. Several mathematical expressions for the PPE signal in specific detection modes (combined back-front configurations and PPE-IRT methods) are also deduced. The “Instrumentation and experiment” section contains two sub-sections. The first describes several examples of set-ups used for both room temperature and temperature-controlled experiments. The second sub-section is dedicated to the configuration of detection cells and to the various sensor/sample assemblies that are currently used in spectroscopic and calorimetric experiments for both liquid and solid samples. The “Applications” section is in fact a collection of experimental results dedicated to the thermal characterization of a wide range of solid and liquid samples. At the end of this section we present some examples that have been selected to convey that the PPE technique is not only useful in the investigation of optical and thermal properties of a variety of condensed matter samples, but also to study physical and chemical processes such as molecular associations, food adulteration or phase transitions. In “Concluding remarks” we summarize the advantages of this technique in spectroscopic and calorimetric applications.
Ključne besede: photopyroelectric spectroscopy, photopyroelectric calorimetry, phase transitions, condensed matter samples, thermal parameters
Objavljeno v RUNG: 16.11.2022; Ogledov: 657; Prenosov: 18
Celotno besedilo (2,87 MB) |
10. Monitoring chemical processes in (photo)catalysts and energy storage materials by operando X-ray absorption spectroscopyIztok Arčon, 2022, objavljeni povzetek znanstvenega prispevka na konferenci (vabljeno predavanje) Opis: X-ray absorption spectroscopy (XAS) is a powerful tool for characterisation of local structure and chemical state of selected elements in different new functional materials and biological or environmental samples. The XAS spectroscopy is based on extremely bright synchrotron radiation X-rays sources, which allow precise characterisation of bulk, nanostructured or highly diluted samples. The rapid development of extremely bright synchrotron sources of X-ray and ultraviolet light in recent years has opened new possibilities for research of matter at the atomic or molecular level, indispensable in the development of new functional nanostructured materials with desired properties. The talk will present the possibilities offered by X-ray absorption spectroscopy with synchrotron light for ex-situ or operando characterization of various functional porous and other nanomaterials, before, after and during their operation [1,2,3,4]. New generation of synchrotron light sources also opened the possibility of combining X-ray absorption with high-resolution emission [5] and inelastic scattering spectroscopy [6], and microscopy with sub-micron resolution [7]. Examples of operando XANES and EXAFS analysis to track changes in the valence states and local structures of selected elements in different energy storage materials and in various (photo)catalysts, during chemical reactions under controlled reaction conditions, will be presented, which provided insight into the dynamic functional properties and reaction mechanisms of these materials. Access to SR facilities of Petra III (beamlines P65, P64 and P01), ESRF (beamlines BM23, ID21, ID26) and Elettra (beamlines XAFS, XRF), for the presented research is kindly acknowledged.
Ključne besede: X-ray absorption spectroscopy, operando XANES, EXAFS, catalysts, batteries
Objavljeno v RUNG: 07.10.2022; Ogledov: 571; Prenosov: 0
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