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Plasmonic lattice nanostructures are of technological interest because of their capacity to manipulate light below the diffraction limit. Here, we present a detailed study of dark and bright modes in the visible and near-infrared energy regime of an inverted plasmonic honeycomb lattice by a combination of Au+ focused ion beam lithography with nanometric resolution, optical and electron spectroscopy, and finite-difference time-domain simulations. The lattice consists of slits carved in a gold thin film, exhibiting hotspots and a set of bright and dark modes. We proposed that some of the dark modes detected by electron energy-loss spectroscopy are caused by antiferroelectric arrangements of the slit polarizations with two times the size of the hexagonal unit cell. The plasmonic resonances take place within the 0.5–2 eV energy range, indicating that they could be suitable for a synergistic coupling with excitons in two-dimensional transition metal dichalcogenides materials or for designing nanoscale sensing platforms based on near-field enhancement over a metallic surface.

Detection of bioparticles is of great importance in electrophoresis, identification of biomass sources, food and water safety, and other areas. It requires a proper model to describe bioparticles’ electromagnetic characteristics. A numerical study of Escherichia coli bacteria during their functional activity was carried out by using two different geometrical models for the cells that considered the bacteria as layered ellipsoids and layered spheres. It was concluded that during cell duplication, the change in the dielectric permittivity of the cell is high enough to be measured at radio frequencies of the order of 50 kHz. An experimental setup based on the capacitive Wheatstone bridge was designed to measure relative changes in permittivity during cell division. In this way, the theoretical model was validated by measuring the dielectric permittivity changes in a cell culture of Escherichia coli ATTC 8739 from WDCM 00012 Vitroids. The spheroidal model was confirmed to be more accurate., This research was funded by the Agencia Estatal de Investigación PID2019-107885GB-C31/AEI/10.13039, PRE2018-084326., Peer Reviewed, Postprint (published version)

Understanding the molecular radiation damage is crucial in radiobiology, molecular physics, and atmospheric science. In this thesis, the initial steps of radiation damage of anhydrous gas-phase molecules and hydrated nanoparticles were studied using synchrotron radiation based electron-ion coincidence spectroscopy and X-ray absorption spectroscopy under vacuum conditions. Electron - ion coincidence spectroscopy was used to study the photofragmentation and molecular dynamics of the isolated gas-phase molecules. In addition to the photofragmentation of the gas-phase molecules, the effect of the initial ionization site, initial molecular geometry, and the intramolecular chemical environment has been studied. In avobenzone, core ionization leads to massive fragmentation, with a slight site-selectivity concerning fragment production. In ortho-aminobenzoic acid, core ionization leads to the production of a hydronium ion, indicating that the importance of functional group's position for double intramolecular hydrogen transfer. X-ray absorption spectroscopy was used to probe hydrated nanoparticles prepared at different relative humidities. In hydrated inorganic and mixed inorganic-organic nanoparticles, water is present in a liquid-like state. With different ranges of relative humidity, the primary hydration layers of the hydrated nanoparticles stays the same. In mixed nanoparticles, there is evidence for interaction between the included organic biomolecule with the inorganic and/or water molecules.

Understanding the molecular radiation damage is crucial in radiobiology, molecular physics, and atmospheric science. In this thesis, the initial steps of radiation damage of anhydrous gas-phase molecules and hydrated nanoparticles were studied using synchrotron radiation based electron-ion coincidence spectroscopy and X-ray absorption spectroscopy under vacuum conditions. Electron - ion coincidence spectroscopy was used to study the photofragmentation and molecular dynamics of the isolated gas-phase molecules. In addition to the photofragmentation of the gas-phase molecules, the effect of the initial ionization site, initial molecular geometry, and the intramolecular chemical environment has been studied. In avobenzone, core ionization leads to massive fragmentation, with a slight site-selectivity concerning fragment production. In ortho-aminobenzoic acid, core ionization leads to the production of a hydronium ion, indicating that the importance of functional group's position for double intramolecular hydrogen transfer. X-ray absorption spectroscopy was used to probe hydrated nanoparticles prepared at different relative humidities. In hydrated inorganic and mixed inorganic-organic nanoparticles, water is present in a liquid-like state. With different ranges of relative humidity, the primary hydration layers of the hydrated nanoparticles stays the same. In mixed nanoparticles, there is evidence for interaction between the included organic biomolecule with the inorganic and/or water molecules.

Understanding the molecular radiation damage is crucial in radiobiology, molecular physics, and atmospheric science. In this thesis, the initial steps of radiation damage of anhydrous gas-phase molecules and hydrated nanoparticles were studied using synchrotron radiation based electron-ion coincidence spectroscopy and X-ray absorption spectroscopy under vacuum conditions. Electron - ion coincidence spectroscopy was used to study the photofragmentation and molecular dynamics of the isolated gas-phase molecules. In addition to the photofragmentation of the gas-phase molecules, the effect of the initial ionization site, initial molecular geometry, and the intramolecular chemical environment has been studied. In avobenzone, core ionization leads to massive fragmentation, with a slight site-selectivity concerning fragment production. In ortho-aminobenzoic acid, core ionization leads to the production of a hydronium ion, indicating that the importance of functional group's position for double intramolecular hydrogen transfer. X-ray absorption spectroscopy was used to probe hydrated nanoparticles prepared at different relative humidities. In hydrated inorganic and mixed inorganic-organic nanoparticles, water is present in a liquid-like state. With different ranges of relative humidity, the primary hydration layers of the hydrated nanoparticles stays the same. In mixed nanoparticles, there is evidence for interaction between the included organic biomolecule with the inorganic and/or water molecules.

Understanding the molecular radiation damage is crucial in radiobiology, molecular physics, and atmospheric science. In this thesis, the initial steps of radiation damage of anhydrous gas-phase molecules and hydrated nanoparticles were studied using synchrotron radiation based electron-ion coincidence spectroscopy and X-ray absorption spectroscopy under vacuum conditions. Electron-ion coincidence spectroscopy was used to study the photofragmentation and molecular dynamics of the isolated gas-phase molecules. In addition to the photofragmentation of the gas-phase molecules, the effect of the initial ionization site, initial molecular geometry, and the intramolecular chemical environment has been studied. In avobenzone, core ionization leads to massive fragmentation, with a slight site-selectivity concerning fragment production. In ortho-aminobenzoic acid, core ionization leads to the production of a hydronium ion, indicating that the importance of functional group’s position for double intramolecular hydrogen transfer. X-ray absorption spectroscopy was used to probe hydrated nanoparticles prepared at different relative humidities. In hydrated inorganic and mixed inorganic-organic nanoparticles, water is present in a liquid-like state. With different ranges of relative humidity, the primary hydration layers of the hydrated nanoparticles stays the same. In mixed nanoparticles, there is evidence for interaction between the included organic biomolecule with the inorganic and/or water molecules., Abstrakti Molekyylitasolla tapahtuvien säteilyvaurioiden ymmärrys on erittäin tärkeää säteilybiologiassa, molekyylifysiikassa ja ilmakehätieteissä. Tässä työssä on tutkittu tyhjiöolosuhteissa säteilyvaurioiden alkuaskeleita vedettömissä kaasumaisissa molekyyleissä ja vettä sisältävissä nanohiukkasissa käyttäen synkrotronisäteilypohjaista elektroni-ionikoinsidenssispektroskopiaa ja röntgenabsorptiospektroskopiaa. Elektroni-ionikoinsidenssispektroskopialla tutkittiin säteilyn aikaansaamaa hajoamista ja molekyylidynamiikkaa eristetyissä kaasumolekyyleissä. Tämän lisäksi tutkittiin, kuinka ensimmäisen ionisaatiotapahtuman paikka, molekyylin geometria ja molekyylin sisäinen kemiallinen ympäristö vaikuttaa näihin prosesseihin. Avobentsonimolekyylin sisäkuoren ionisaatio johtaa molekyylin hajoamiseen lukuisiksi eri hajoamistuotteiksi, ja hajoamistuotteiden saannin todettiin riippuvan vain vähän ionisoidusta sisäkuoresta. Orto-aminobentsoehapossa sisäkuoren ionisaation havaittiin tuottavan kahden vedyn siirtymisen vaativaa hydroniumionia, ja tuoton havaittiin riippuvan funktionaalisten ryhmien keskinäisestä paikasta. Röntgenabsorptiospektroskopiaa hyödynnettiin eri suhteellisissa ilmankosteuksissa valmistettujen nanohiukkasten tutkimuksessa. Näissä epäorgaanisissa ja saostetuissa orgaanisissa-epäorgaanisissa nanohiukkasissa veden havaittiin olevan nesteenkaltaisessa olomuodossa. Saostetuissa nanohiukkasissa nähtiin myös merkkejä orgaanisen biomolekyylin ja epäorgaanisen ja/tai veden välisestä vuorovaikutuksesta., Sammanfattning Förståelse av molekylära strålningsskador är avgörande inom radiobiologi, molekylär fysik och atmosfärsvetenskap. I denna avhandling studerades strålningsskadornas inledande steg hos gasfasmolekyler och hydratiserade nanopartiklar med hjälp av synkrotronstrålningsbaserad elektron-jon-koincidensspektroskopi och röntgenabsorptionsspektroskopi under vakuumförhållanden. Elektron-jon-koincidensspektroskopi användes för att studera fotofragmentering och molekylär dynamik hos de isolerade gasfasmolekylerna. Förutom fotofragmenteringen av gasfasmolekylerna har effekten av den initiala joniseringsplatsen i molekylen, den initiala molekylära geometrin och den intramolekyl ära kemiska miljön studerats. I avobenzon leder innerskalsjonisering till massiv fragmentering med liten platsselektivitet beträffande fragmentproduktion. I orto-aminobensoesyra leder innerskalsjonisering till produktion av en hydroniumjon, vilket pekar på vikten av funktionella gruppers position för sådan dubbel intramolekylär väteöverföring. Röntgenabsorptionsspektroskopi användes för att studera hydratiserade nanopartiklar framställda vid varierande relativa fuktighet. I hydratiserade inorganiska och blandade inorganiska-organiska nanopartiklar finns vatten i vätskeformigt tillstånd. De primära hydratiseringsskalen i de hydratiserade nanopartiklarna opåverkade av de olika relativa fuktighetsnivåerna. I blandade nanopartiklar finns det bevis för växelverkan mellan de inkluderade organiska biomolekylerna och de inorganiska jonerna och/eller vattenmolekylerna.

Understanding the molecular radiation damage is crucial in radiobiology, molecular physics, and atmospheric science. In this thesis, the initial steps of radiation damage of anhydrous gas-phase molecules and hydrated nanoparticles were studied using synchrotron radiation based electron-ion coincidence spectroscopy and X-ray absorption spectroscopy under vacuum conditions. Electron - ion coincidence spectroscopy was used to study the photofragmentation and molecular dynamics of the isolated gas-phase molecules. In addition to the photofragmentation of the gas-phase molecules, the effect of the initial ionization site, initial molecular geometry, and the intramolecular chemical environment has been studied. In avobenzone, core ionization leads to massive fragmentation, with a slight site-selectivity concerning fragment production. In ortho-aminobenzoic acid, core ionization leads to the production of a hydronium ion, indicating that the importance of functional group's position for double intramolecular hydrogen transfer. X-ray absorption spectroscopy was used to probe hydrated nanoparticles prepared at different relative humidities. In hydrated inorganic and mixed inorganic-organic nanoparticles, water is present in a liquid-like state. With different ranges of relative humidity, the primary hydration layers of the hydrated nanoparticles stays the same. In mixed nanoparticles, there is evidence for interaction between the included organic biomolecule with the inorganic and/or water molecules.

Understanding the molecular radiation damage is crucial in radiobiology, molecular physics, and atmospheric science. In this thesis, the initial steps of radiation damage of anhydrous gas-phase molecules and hydrated nanoparticles were studied using synchrotron radiation based electron-ion coincidence spectroscopy and X-ray absorption spectroscopy under vacuum conditions. Electron - ion coincidence spectroscopy was used to study the photofragmentation and molecular dynamics of the isolated gas-phase molecules. In addition to the photofragmentation of the gas-phase molecules, the effect of the initial ionization site, initial molecular geometry, and the intramolecular chemical environment has been studied. In avobenzone, core ionization leads to massive fragmentation, with a slight site-selectivity concerning fragment production. In ortho-aminobenzoic acid, core ionization leads to the production of a hydronium ion, indicating that the importance of functional group's position for double intramolecular hydrogen transfer. X-ray absorption spectroscopy was used to probe hydrated nanoparticles prepared at different relative humidities. In hydrated inorganic and mixed inorganic-organic nanoparticles, water is present in a liquid-like state. With different ranges of relative humidity, the primary hydration layers of the hydrated nanoparticles stays the same. In mixed nanoparticles, there is evidence for interaction between the included organic biomolecule with the inorganic and/or water molecules.

Silicon Drift Detectors, widely employed in high-resolution and high-rate X-ray applications, are considered here with interest also for electron detection. The accurate measurement of the tritium beta decay is the core of the TRISTAN (TRitium Investigation on STerile to Active Neutrino mixing) project. This work presents the characterisation of a single-pixel SDD detector with a mono-energetic electron beam obtained from a Scanning Electron Microscope. The suitability of the SDD to detect electrons, in the energy range spanning from few keV to tens of keV, is demonstrated. Experimental measurements reveal a strong effect of the detector's entrance window structure on the observed energy response. A detailed detector model is therefore necessary to reconstruct the spectrum of an unknown beta-decay source.

The Avobenzone (AVOB) molecule is very photoactive and undergoes irreversible degradation upon irradiation. We studied its valence and core-level (C1s and O1s) photoionisation and subsequent photofragmentation with photoelectron spectroscopy and photoelectron-photoion-photoion coincidence (PEPIPICO) spectroscopy. AVOB is one of the largest molecules studied with this technique. The results show that the AVOB molecule dissociates into an extensive range of fragments by different pathways with little element or site-selectivity. The coincident maps were used to determine selected fragment separation sequences by analysing the slopes of patterns from ion pairs after the core ionisation. Charge delocalisation over the benzene rings and their relative stability favor fragmentation by cleavage of the bridge between them.

We present a combined experimental and theoretical study of the double-core-hole photoelectron spectrum obtained in isolated water molecules irradiated with hard x-rays above the oxygen K -2 threshold. States of the type O K -2V and multiply excited states are created by single-photon absorption and subsequent one-electron emission. A detailed analysis enabled by high experimental resolution reveals dissociative nuclear dynamics in the K-2V pre-edge states. At the binding energies above the K- 2 double-ionization potential, a complex spectral pattern is observed and attributed to highly excited states involving multiple shake-up excitation processes with the aid of state- of-the-art theoretical calculations. A strong broadening due to the nuclear motion indicates a highly dissociative nature of these multiply excited states, in agreement with the theoretical analysis.

We have observed formation of Rydberg series superimposed on the Ar (L3M2,3M2,3) Auger electron spectral profile with photoexcitation just above the 2p(3/2)(-1) photoionization threshold. This is due to the recapture of photoelectrons induced by post-collision interaction between the Auger electron and photoelectron: Ar+ 2p(3/2)(-1) + e(-) -> Ar+ 3p(-2)ml + e(-). The intensity distribution of the angular momentum state resolved Rydberg peaks revealed prominent conjugate peaks due to angular momentum exchange between photoelectrons and Auger electrons in the process. In addition, we measured the 2p(3/2)(-1)nl -> 3p(-2)ml + e(-) resonant Auger spectra with high resolution below the 2p(3/2)(-1) threshold. Our results showed that conjugate shake-up/down 2p(3/2)(-1)nd -> 3p(-2)mp + e(-) processes are stronger than the direct 2p(3/2)(-1)nd -> 3p(-2)ms, (m-1)d + e(-) processes in the spectator Auger processes, implying a strong angular momentum exchange effect between photoelectron and Auger electron.

The Avobenzone (AVOB) molecule is very photoactive and undergoes irreversible degradation upon irradiation. We studied its valence and core-level (C1s and O1s) photoionisation and subsequent photofragmentation with photoelectron spectroscopy and photoelectron-photoion-photoion coincidence (PEPIPICO) spectroscopy. AVOB is one of the largest molecules studied with this technique. The results show that the AVOB molecule dissociates into an extensive range of fragments by different pathways with little element or site-selectivity. The coincident maps were used to determine selected fragment separation sequences by analysing the slopes of patterns from ion pairs after the core ionisation. Charge delocalisation over the benzene rings and their relative stability favor fragmentation by cleavage of the bridge between them.

The Avobenzone (AVOB) molecule is very photoactive and undergoes irreversible degradation upon irradiation. We studied its valence and core-level (C1s and O1s) photoionisation and subsequent photofragmentation with photoelectron spectroscopy and photoelectron-photoion-photoion coincidence (PEPIPICO) spectroscopy. AVOB is one of the largest molecules studied with this technique. The results show that the AVOB molecule dissociates into an extensive range of fragments by different pathways with little element or site-selectivity. The coincident maps were used to determine selected fragment separation sequences by analysing the slopes of patterns from ion pairs after the core ionisation. Charge delocalisation over the benzene rings and their relative stability favor fragmentation by cleavage of the bridge between them.

The Avobenzone (AVOB) molecule is very photoactive and undergoes irreversible degradation upon irradiation. We studied its valence and core-level (C1s and O1s) photoionisation and subsequent photofragmentation with photoelectron spectroscopy and photoelectron-photoion-photoion coincidence (PEPIPICO) spectroscopy. AVOB is one of the largest molecules studied with this technique. The results show that the AVOB molecule dissociates into an extensive range of fragments by different pathways with little element or site-selectivity. The coincident maps were used to determine selected fragment separation sequences by analysing the slopes of patterns from ion pairs after the core ionisation. Charge delocalisation over the benzene rings and their relative stability favor fragmentation by cleavage of the bridge between them.

We present the analysis of a family of nanotubes (NTs) based on the quaternary misfit layered compound (MLC) YxLa1-xS-TaS2. The NTs were successfully synthesized within the whole range of possible compositions via the chemical vapor transport technique. In-depth analysis of the NTs using electron microscopy and spectroscopy proves the in-phase (partial) substitution of La by Y in the (La,Y)S subsystem and reveals structural changes compared to the previously reported LaS-TaS2 MLC-NTs. The observed structure can be linked to the slightly different lattice parameters of LaS and YS. Raman spectroscopy and infrared transmission measurements reveal the tunability of the plasmonic and vibrational properties. Density-functional theory calculations showed that the YxLa1-xS-TaS2 MLCs are stable in all compositions. Moreover, the calculations indicated that substitution of La by Sc atoms is electronically not favorable, which explains our failed attempt to synthesize these MLC and NTs thereof. © 2020 American Chemical Society.

The Avobenzone (AVOB) molecule is very photoactive and undergoes irreversible degradation upon irradiation. We studied its valence and core-level (C1s and O1s) photoionisation and subsequent photofragmentation with photoelectron spectroscopy and photoelectron-photoion-photoion coincidence (PEPIPICO) spectroscopy. AVOB is one of the largest molecules studied with this technique. The results show that the AVOB molecule dissociates into an extensive range of fragments by different pathways with little element or site-selectivity. The coincident maps were used to determine selected fragment separation sequences by analysing the slopes of patterns from ion pairs after the core ionisation. Charge delocalisation over the benzene rings and their relative stability favor fragmentation by cleavage of the bridge between them.

In this thesis the electronic structure and dynamics of iodine, krypton and bromine atoms in isolated and molecular forms are investigated through K-shell photoexcitation and subsequent Auger decay. The experimental studies are carried out using hard x-ray photoelectron spectroscopic techniques and the theoretical work by applying relativistic ab initio quantum mechanical models. The reported photoelectron spectra from iodine compounds CH3I and CF3I have the highest binding energy, 33.2 keV, recorded from any molecule in the gas phase up to date. From the spectra it is shown that chemical shifts are observable even at such deep core orbitals. From krypton a detailed analysis of Auger decay and Fluorescence cascade following K and L-shell ionization up to quadruple ionized states is presented. The work concerning bromine provides an analysis of photoionization, excitation, lifetime, Auger decay and nuclear dynamics around the K-edge of HBr molecule.

We present the analysis of a family of nanotubes (NTs) based on the quaternary misfit layered compound (MLC) YxLa1–xS-TaS2. The NTs were successfully synthesized within the whole range of possible compositions via the chemical vapor transport technique. In-depth analysis of the NTs using electron microscopy and spectroscopy proves the in-phase (partial) substitution of La by Y in the (La,Y)S subsystem and reveals structural changes compared to the previously reported LaS-TaS2 MLC-NTs. The observed structure can be linked to the slightly different lattice parameters of LaS and YS. Raman spectroscopy and infrared transmission measurements reveal the tunability of the plasmonic and vibrational properties. Density-functional theory calculations showed that the YxLa1–xS-TaS2 MLCs are stable in all compositions. Moreover, the calculations indicated that substitution of La by Sc atoms is electronically not favorable, which explains our failed attempt to synthesize these MLC and NTs thereof.

The Avobenzone (AVOB) molecule is very photoactive and undergoes irreversible degradation upon irradiation. We studied its valence and core-level (C1s and O1s) photoionisation and subsequent photofragmentation with photoelectron spectroscopy and photoelectron-photoion-photoion coincidence (PEPIPICO) spectroscopy. AVOB is one of the largest molecules studied with this technique. The results show that the AVOB molecule dissociates into an extensive range of fragments by different pathways with little element or site-selectivity. The coincident maps were used to determine selected fragment separation sequences by analysing the slopes of patterns from ion pairs after the core ionisation. Charge delocalisation over the benzene rings and their relative stability favor fragmentation by cleavage of the bridge between them.

Photoionization is one of the most fundamental photoreactions that leads to the ejection of an electron and the formation of an ion. With the help of modern 3D momentum imaging spectrometers, the interplay between the time and frequency domain upon ionization is studied. In this work, single photoionization of helium is investigated in the few-cycle pulse regime of the driving infrared laser pulses with ultrashort attosecond pulses in a dressing infrared field. By varying the carrier-to-envelope phase of the infrared field to modify the spectro-temporal structure of the attosecond pulses, we analyze how the infrared field impacts the measured angularly-resolved photoelectron energy distribution. To this end, a newly built coincidence 3D momentum spectrometer was used. A thorough understanding of the experiment is achieved by using simulations within the strong field approximation. This analysis allows us to separate our observation into two scenarios, one at two attosecond pulses when the carrier-to-envelope phase is $\pi/2$ and the second one at three attosecond pulses when the carrier-to-envelope phase is 0 or $\pi$. When the dressing infrared field is added, the photoelectron spectrum changes in comparison to photoionization with attosecond pulses only. While two attosecond pulses in the dressing infrared field modify the photoelectron spectrum in a continuous way, we observe sidebands appearing in the spectrum generated by three pulses in the dressing infrared field. Finally, the resolution of the spectrometer is studied before and after an upgrade of the spectrometer was performed in the context of this work. This study allows us to understand the limiting factors of the energy resolution. In particular, it shows that the resolution is essentially limited by the source volume of the emitted particles, while the magnetic field does not limit the resolution as it was expected.

Photoionization is one of the most fundamental photoreactions that leads to the ejection of an electron and the formation of an ion. With the help of modern 3D momentum imaging spectrometers, the interplay between the time and frequency domain upon ionization is studied. In this work, single photoionization of helium is investigated in the few-cycle pulse regime of the driving infrared laser pulses with ultrashort attosecond pulses in a dressing infrared field. By varying the carrier-to-envelope phase of the infrared field to modify the spectro-temporal structure of the attosecond pulses, we analyze how the infrared field impacts the measured angularly-resolved photoelectron energy distribution. To this end, a newly built coincidence 3D momentum spectrometer was used. A thorough understanding of the experiment is achieved by using simulations within the strong field approximation. This analysis allows us to separate our observation into two scenarios, one at two attosecond pulses when the carrier-to-envelope phase is $\pi/2$ and the second one at three attosecond pulses when the carrier-to-envelope phase is 0 or $\pi$. When the dressing infrared field is added, the photoelectron spectrum changes in comparison to photoionization with attosecond pulses only. While two attosecond pulses in the dressing infrared field modify the photoelectron spectrum in a continuous way, we observe sidebands appearing in the spectrum generated by three pulses in the dressing infrared field. Finally, the resolution of the spectrometer is studied before and after an upgrade of the spectrometer was performed in the context of this work. This study allows us to understand the limiting factors of the energy resolution. In particular, it shows that the resolution is essentially limited by the source volume of the emitted particles, while the magnetic field does not limit the resolution as it was expected.

New experimental methods for synthesis of low dimensional carbon structures still attract considerable attention, many of them based on catalytically driven processes. In this contribution we present REELS and Auger spectroscopy study of Ni-induced layer exchange in Ni/C-bilayer thin film system. EELS spectroscopy in reflected mode (REELS) and Auger electron spectroscopy (AES) were employed to characterize the structure, homogeneity and quality of carbon and nickel film (each having thickness around 50 nm) and their interface between, before and after thermal annealing at 700 °C. AES mapping and depth profiling revealed a layer exchange between the layers after thermal annealing, accompanied by partial nickel diffusion into MgO substrate. REELS analysis showed successful structural transformation of initially amorphous carbon layer into compact graphitic one. The transformed carbon layer has a slightly rippled surface as confirmed by topological backscattered electron imaging.

New experimental methods for synthesis of low dimensional carbon structures still attract considerable attention, many of them based on catalytically driven processes. In this contribution we present REELS and Auger spectroscopy study of Ni-induced layer exchange in Ni/C-bilayer thin film system. EELS spectroscopy in reflected mode (REELS) and Auger electron spectroscopy (AES) were employed to characterize the structure, homogeneity and quality of carbon and nickel film (each having thickness around 50 nm) and their interface between, before and after thermal annealing at 700 °C. AES mapping and depth profiling revealed a layer exchange between the layers after thermal annealing, accompanied by partial nickel diffusion into MgO substrate. REELS analysis showed successful structural transformation of initially amorphous carbon layer into compact graphitic one. The transformed carbon layer has a slightly rippled surface as confirmed by topological backscattered electron imaging.

Photoionization is one of the most fundamental photoreactions that leads to the ejection of an electron and the formation of an ion. With the help of modern 3D momentum imaging spectrometers, the interplay between the time and frequency domain upon ionization is studied. In this work, single photoionization of helium is investigated in the few-cycle pulse regime of the driving infrared laser pulses with ultrashort attosecond pulses in a dressing infrared field. By varying the carrier-to-envelope phase of the infrared field to modify the spectro-temporal structure of the attosecond pulses, we analyze how the infrared field impacts the measured angularly-resolved photoelectron energy distribution. To this end, a newly built coincidence 3D momentum spectrometer was used. A thorough understanding of the experiment is achieved by using simulations within the strong field approximation. This analysis allows us to separate our observation into two scenarios, one at two attosecond pulses when the carrier-to-envelope phase is $\pi/2$ and the second one at three attosecond pulses when the carrier-to-envelope phase is 0 or $\pi$. When the dressing infrared field is added, the photoelectron spectrum changes in comparison to photoionization with attosecond pulses only. While two attosecond pulses in the dressing infrared field modify the photoelectron spectrum in a continuous way, we observe sidebands appearing in the spectrum generated by three pulses in the dressing infrared field. Finally, the resolution of the spectrometer is studied before and after an upgrade of the spectrometer was performed in the context of this work. This study allows us to understand the limiting factors of the energy resolution. In particular, it shows that the resolution is essentially limited by the source volume of the emitted particles, while the magnetic field does not limit the resolution as it was expected.

The adsorption of purely organic chiral molecules on ferromagnetic Co thin films is studied under ultra high vacuum conditions by means of synchrotron radiation-based electron spectroscopies, namely X-ray absorption and ultraviolet photoemission. X-ray absorption reveals that enantiomers with opposite handedness (R,R) - and (S,S)- of two different molecules adsorb with different strength on the Co surfaces and their valence band photoemission spectra also display distinctive features. In view of the recent reports describing the chiral-induced spin selectivity (CISS) effect these results lead us to consider the possibility that some enantiosensitivity may appear when bonding chiral molecules to a substrate with an initial asymmetry in the population of the different spin orientations.

The simultaneous detection of energy, momentum and temporal information in electron spectroscopy is the key aspect to enhance the detection efficiency in order to broaden the range of scientific applications. Employing a novel 60 degrees wide angle acceptance lens system, based on an additional accelerating electron optical element, leads to a significant enhancement in transmission over the previously employed 30 degrees electron lenses. Due to the performance gain, optimized capabilities for time resolved electron spectroscopy and other high transmission applications with pulsed ionizing radiation have been obtained. The energy resolution and transmission have been determined experimentally utilizing BESSY II as a photon source. Four different and complementary lens modes have been characterized. (C) 2017 The Authors. Published by Elsevier B.V.

Computational quantum chemistry methods have been applied in two particular cases: to provide insight to photoionization induced fragmentation of HgBr2 and HgCl2 molecules, and to study core-electron binding energies and chemical shifts of molecules in liquid, surface adsorbed and polymeric environments in the framework of quantum mechanics/molecular mechanics (QM/MM). In the photodissociation studies the computational work is based on the relativistic Dirac equation as the systems present strong spin-orbit interaction affecting the fragmentation processes. In the QM/MM studies of ethanol-water mixtures and molecules physisorbed on silver surfaces the structures are provided by classical molecular dynamics simulations to analyze the distribution of the binding energies of core-orbitals and effects of their surroundings. In the case of polymethyl methacrylate polymer the impact of a QM-MM boundary and a polymeric environment are studied. The theoretical backgrounds of the computational methods applied and the obtained results are discussed., This thesis is for a double degree PhD done in KTH Royal institute of Technology and University of Oulu.QC 20180502

The simultaneous detection of energy, momentum and temporal information in electron spectroscopy is the key aspect to enhance the detection efficiency in order to broaden the range of scientific applications. Employing a novel 60 degrees wide angle acceptance lens system, based on an additional accelerating electron optical element, leads to a significant enhancement in transmission over the previously employed 30 degrees electron lenses. Due to the performance gain, optimized capabilities for time resolved electron spectroscopy and other high transmission applications with pulsed ionizing radiation have been obtained. The energy resolution and transmission have been determined experimentally utilizing BESSY II as a photon source. Four different and complementary lens modes have been characterized. (C) 2017 The Authors. Published by Elsevier B.V.

The simultaneous detection of energy, momentum and temporal information in electron spectroscopy is the key aspect to enhance the detection efficiency in order to broaden the range of scientific applications. Employing a novel 60 degrees wide angle acceptance lens system, based on an additional accelerating electron optical element, leads to a significant enhancement in transmission over the previously employed 30 degrees electron lenses. Due to the performance gain, optimized capabilities for time resolved electron spectroscopy and other high transmission applications with pulsed ionizing radiation have been obtained. The energy resolution and transmission have been determined experimentally utilizing BESSY II as a photon source. Four different and complementary lens modes have been characterized. (C) 2017 The Authors. Published by Elsevier B.V.

Computational quantum chemistry methods have been applied in two particular cases: to provide insight to photoionization induced fragmentation of HgBr2 and HgCl2 molecules, and to study core-electron binding energies and chemical shifts of molecules in liquid, surface adsorbed and polymeric environments in the framework of quantum mechanics/molecular mechanics (QM/MM). In the photodissociation studies the computational work is based on the relativistic Dirac equation as the systems present strong spin-orbit interaction affecting the fragmentation processes. In the QM/MM studies of ethanol-water mixtures and molecules physisorbed on silver surfaces the structures are provided by classical molecular dynamics simulations to analyze the distribution of the binding energies of core-orbitals and effects of their surroundings. In the case of polymethyl methacrylate polymer the impact of a QM-MM boundary and a polymeric environment are studied. The theoretical backgrounds of the computational methods applied and the obtained results are discussed., This thesis is for a double degree PhD done in KTH Royal institute of Technology and University of Oulu.QC 20180502

The simultaneous detection of energy, momentum and temporal information in electron spectroscopy is the key aspect to enhance the detection efficiency in order to broaden the range of scientific applications. Employing a novel 60 degrees wide angle acceptance lens system, based on an additional accelerating electron optical element, leads to a significant enhancement in transmission over the previously employed 30 degrees electron lenses. Due to the performance gain, optimized capabilities for time resolved electron spectroscopy and other high transmission applications with pulsed ionizing radiation have been obtained. The energy resolution and transmission have been determined experimentally utilizing BESSY II as a photon source. Four different and complementary lens modes have been characterized. (C) 2017 The Authors. Published by Elsevier B.V.

The simultaneous detection of energy, momentum and temporal information in electron spectroscopy is the key aspect to enhance the detection efficiency in order to broaden the range of scientific applications. Employing a novel 60 degrees wide angle acceptance lens system, based on an additional accelerating electron optical element, leads to a significant enhancement in transmission over the previously employed 30 degrees electron lenses. Due to the performance gain, optimized capabilities for time resolved electron spectroscopy and other high transmission applications with pulsed ionizing radiation have been obtained. The energy resolution and transmission have been determined experimentally utilizing BESSY II as a photon source. Four different and complementary lens modes have been characterized. (C) 2017 The Authors. Published by Elsevier B.V.

The simultaneous detection of energy, momentum and temporal information in electron spectroscopy is the key aspect to enhance the detection efficiency in order to broaden the range of scientific applications. Employing a novel 60 degrees wide angle acceptance lens system, based on an additional accelerating electron optical element, leads to a significant enhancement in transmission over the previously employed 30 degrees electron lenses. Due to the performance gain, optimized capabilities for time resolved electron spectroscopy and other high transmission applications with pulsed ionizing radiation have been obtained. The energy resolution and transmission have been determined experimentally utilizing BESSY II as a photon source. Four different and complementary lens modes have been characterized. (C) 2017 The Authors. Published by Elsevier B.V.

The simultaneous detection of energy, momentum and temporal information in electron spectroscopy is the key aspect to enhance the detection efficiency in order to broaden the range of scientific applications. Employing a novel 60 degrees wide angle acceptance lens system, based on an additional accelerating electron optical element, leads to a significant enhancement in transmission over the previously employed 30 degrees electron lenses. Due to the performance gain, optimized capabilities for time resolved electron spectroscopy and other high transmission applications with pulsed ionizing radiation have been obtained. The energy resolution and transmission have been determined experimentally utilizing BESSY II as a photon source. Four different and complementary lens modes have been characterized. (C) 2017 The Authors. Published by Elsevier B.V.

Computational quantum chemistry methods have been applied in two particular cases: to provide insight to photoionization induced fragmentation of HgBr2 and HgCl2 molecules, and to study core-electron binding energies and chemical shifts of molecules in liquid, surface adsorbed and polymeric environments in the framework of quantum mechanics/molecular mechanics (QM/MM). In the photodissociation studies the computational work is based on the relativistic Dirac equation as the systems present strong spin-orbit interaction affecting the fragmentation processes. In the QM/MM studies of ethanol-water mixtures and molecules physisorbed on silver surfaces the structures are provided by classical molecular dynamics simulations to analyze the distribution of the binding energies of core-orbitals and effects of their surroundings. In the case of polymethyl methacrylate polymer the impact of a QM-MM boundary and a polymeric environment are studied. The theoretical backgrounds of the computational methods applied and the obtained results are discussed., This thesis is for a double degree PhD done in KTH Royal institute of Technology and University of Oulu.QC 20180502

Computational quantum chemistry methods have been applied in two particular cases: to provide insight to photoionization induced fragmentation of HgBr2 and HgCl2 molecules, and to study core-electron binding energies and chemical shifts of molecules in liquid, surface adsorbed and polymeric environments in the framework of quantum mechanics/molecular mechanics (QM/MM). In the photodissociation studies the computational work is based on the relativistic Dirac equation as the systems present strong spin-orbit interaction affecting the fragmentation processes. In the QM/MM studies of ethanol-water mixtures and molecules physisorbed on silver surfaces the structures are provided by classical molecular dynamics simulations to analyze the distribution of the binding energies of core-orbitals and effects of their surroundings. In the case of polymethyl methacrylate polymer the impact of a QM-MM boundary and a polymeric environment are studied. The theoretical backgrounds of the computational methods applied and the obtained results are discussed., This thesis is for a double degree PhD done in KTH Royal institute of Technology and University of Oulu.QC 20180502

Computational quantum chemistry methods have been applied in two particular cases: to provide insight to photoionization induced fragmentation of HgBr2 and HgCl2 molecules, and to study core-electron binding energies and chemical shifts of molecules in liquid, surface adsorbed and polymeric environments in the framework of quantum mechanics/molecular mechanics (QM/MM). In the photodissociation studies the computational work is based on the relativistic Dirac equation as the systems present strong spin-orbit interaction affecting the fragmentation processes. In the QM/MM studies of ethanol-water mixtures and molecules physisorbed on silver surfaces the structures are provided by classical molecular dynamics simulations to analyze the distribution of the binding energies of core-orbitals and effects of their surroundings. In the case of polymethyl methacrylate polymer the impact of a QM-MM boundary and a polymeric environment are studied. The theoretical backgrounds of the computational methods applied and the obtained results are discussed., This thesis is for a double degree PhD done in KTH Royal institute of Technology and University of Oulu.QC 20180502

Multilayer nanolaminate TiAlN/Ag and Al2O3/Ag metal-insulator-metal (MIM) coatings with thicknesses of individual layers from a few to several hundreds of nanometers were fabricated by direct current magnetron sputtering. Their optical transmittance and reflectance spectra were measured for photon energies 1–5 eV (1240–248 nm). The spectra were non-monotonous as their transmission and reflection bands were strongly dependent on the coating architecture. A set of advanced electron spectroscopy methods was used to analyse the electronic structure of the coatings controlling optical properties. Energies of plasmons peaks and the distribution of their intensities are functions of the Ag layers thickness as well as the composition and thickness of the dielectric nanolayers in the MIM nanocomposite. Statistical analysis established the cross-correlations between geometrical parameters of the coatings, transmissions and reflection bands on the optical spectra and parameters of the electronic structure. Particularly, the blue side of the transmittance band is controlled by plasmons while the dielectric band gap determines the transmittance of the red side. The obtained experimental results allowed us to fulfil the computed architectural design of a multilayer Al2O3/Ag coating with a narrow bandwidth in the visible light region and strong reflection in the infrared and ultraviolet regions.

We analyse the valence electronic structure of cobalt phthalocyanine (CoPc) by means of optimally tuning a range-separated hybrid functional. The tuning is performed by modifying both the amount of short-range exact exchange (α) included in the hybrid functional and the range-separation parameter (γ), with two strategies employed for finding the optimal γ for each α. The influence of these two parameters on the structural, electronic, and magnetic properties of CoPc is thoroughly investigated. The electronic structure is found to be very sensitive to the amount and range in which the exact exchange is included. The electronic structure obtained using the optimal parameters is compared to gas-phase photo-electron data and GW calculations, with the unoccupied states additionally compared with inverse photo-electron spectroscopy measurements. The calculated spectrum with tuned γ, determined for the optimal value of α = 0.1, yields a very good agreement with both experimental results and with GW calculations that well-reproduce the experimental data., QC 20170817

The Project 8 collaboration is taking a phased approach to developing an experimental search for the absolute neutrino mass scale, based on a novel technique, Cyclotron Radiation Emission Spectroscopy. The first phase was a demonstration of this new spectroscopy technique using a well understood source of narrow conversion electron lines, 83mKr, as a proof of principle. Results from the first successful operation of the detector are presented, demonstrating the viability of the approach. The strong conversion electron lines near 17.8, 30.4, and 32 keV were observed with full width at half maximum between 140 eV and 15 eV depending on the choice of trapping configuration used. Various upgrades were made to the detector prior to its being operated with the specific goal of determining a performance baseline for planning future phases. These included alternative trapping configurations, with which the observed full width at half maximum has been improved to 3.6 eV. Evaluation of the event reconstruction and data quality are presented based on this data collection period. Areas where improvements will be required for phase II, when the approach will be used for the first time to measure a electrons from a continuous spectrum, are identified.

A simple method for the energy resolution measurement of a spectrometer, working in the fixed analyser transmission mode, is proposed and used to determine the resolution of a SPECS Phoibos 100 spectrometer, being a part of an X-ray Photoelectron Spectroscopy (XPS) setup. The spectrometer resolution was obtained from the 0 is photoelectron line profiles, taken from the oxidized boron-doped silicon single crystal vs. the analyzer pass energy. The measurements were performed for two entrance slits having respective widths of 1 mm and 7 mm. An excellent agreement with the theoretical expectations was obtained for the narrower slit, showing linear dependence on the pass energy. As for the wider slit, agreement with theory is achieved only for lower pass energies. At higher pass energies, the resolution shows non-linear behaviour and even saturation, while the analyzer transmission continues to grow. The instrumental function of the whole XPS system is determined as a convolution of the spectrometer instrumental function and the X-ray energy profile. The usefulness of the total instrumental function for the analysis of valence band spectra was also tested. For that purpose, a novel deconvolution procedure is introduced, giving a possibility to analytically calculate the position of the valence band maximum, providing excellent agreement in the case of high resolution spectra. When the valence band spectra are taken in lower resolution, deconvolution efficiently reduces the spectrum deviations due to the lower resolution, although the valence band maximum determination is less precise. (C) 2017 Elsevier B.V. All rights reserved.

The Project 8 collaboration is taking a phased approach to developing an experimental search for the absolute neutrino mass scale, based on a novel technique, Cyclotron Radiation Emission Spectroscopy. The first phase was a demonstration of this new spectroscopy technique using a well understood source of narrow conversion electron lines, 83mKr, as a proof of principle. Results from the first successful operation of the detector are presented, demonstrating the viability of the approach. The strong conversion electron lines near 17.8, 30.4, and 32 keV were observed with full width at half maximum between 140 eV and 15 eV depending on the choice of trapping configuration used. Various upgrades were made to the detector prior to its being operated with the specific goal of determining a performance baseline for planning future phases. These included alternative trapping configurations, with which the observed full width at half maximum has been improved to 3.6 eV. Evaluation of the event reconstruction and data quality are presented based on this data collection period. Areas where improvements will be required for phase II, when the approach will be used for the first time to measure a electrons from a continuous spectrum, are identified.

A simple method for the energy resolution measurement of a spectrometer, working in the fixed analyser transmission mode, is proposed and used to determine the resolution of a SPECS Phoibos 100 spectrometer, being a part of an X-ray Photoelectron Spectroscopy (XPS) setup. The spectrometer resolution was obtained from the 0 is photoelectron line profiles, taken from the oxidized boron-doped silicon single crystal vs. the analyzer pass energy. The measurements were performed for two entrance slits having respective widths of 1 mm and 7 mm. An excellent agreement with the theoretical expectations was obtained for the narrower slit, showing linear dependence on the pass energy. As for the wider slit, agreement with theory is achieved only for lower pass energies. At higher pass energies, the resolution shows non-linear behaviour and even saturation, while the analyzer transmission continues to grow. The instrumental function of the whole XPS system is determined as a convolution of the spectrometer instrumental function and the X-ray energy profile. The usefulness of the total instrumental function for the analysis of valence band spectra was also tested. For that purpose, a novel deconvolution procedure is introduced, giving a possibility to analytically calculate the position of the valence band maximum, providing excellent agreement in the case of high resolution spectra. When the valence band spectra are taken in lower resolution, deconvolution efficiently reduces the spectrum deviations due to the lower resolution, although the valence band maximum determination is less precise. (C) 2017 Elsevier B.V. All rights reserved.

We carried out numerical simulations on multilayer plasmon excitations by resonant energy transfer. A formal derivation of the transfer rate from the plasmons to the Wannier excitons was performed. We stimulated fluorescence and compared our results with the conventional organic/inorganic hybrid organic light-emitting diode (OLEDs). We formulated electron energy loss spectroscopy (EELS) for multilayer epitaxial grapheme. Our derivation of the general angles-resolved EELS spectra for transmission and reflection is based on the prescribed electron trajectory. In particular, we were interested in application of the theory to various multi-layer electron gas (MLEG) configurations, i.e., epitaxial vs. exfoliated graphene. We did a comparison with the available experimental data to see the effect of the gap between the valence and conduction bands.

Three techniques of spin labeling have been applied to nanostructured SiO2 and have been tested by electron paramagnetic resonance spectroscopy of pH-sensitive nitroxide radicals (NRs). The best technique was based on preliminary interaction of the pH-sensitive NR bromomethyl-2,2,3,5,5-pentamethylimidazoline-1-oxyl with aminopropyltriethoxy-silane (APTES) in the presence of trioctylamine and further treatment of the nanostructured SiO2 with the hydrolyzed product and acetic anhydride. It was found that there are two types of location of the pH-sensitive NRs (spin labels) on the surface of nanostructured silica. The spin labels of the first type located near the surface of nanostructured SiO2 (“slow-motional” NR) have been used to measure near-surface electrical potential at the site of NR N–O• fragment location, q equal to −90 mV. The NR molecules of the second type which were positioned well far from the nanostructured SiO2 surface (“fast-motional” NRs) were employed to establish the regularities of mutual changes in the NR form and nanoparticle surface charge with variations in pH of external bulk solution (pHext). The pH-sensitive NRs covalently attached to the SiO2 surface were successfully employed for the study of surface charge in the drying process with a rise of temperature up to 375 K. A negative surface charge was shown to decrease due to reducing an ionization degree of the surface silanol groups. This process was found to be reversible at re-adsorption of water molecules. © 2015, Springer-Verlag Wien.

Three techniques of spin labeling have been applied to nanostructured SiO2 and have been tested by electron paramagnetic resonance spectroscopy of pH-sensitive nitroxide radicals (NRs). The best technique was based on preliminary interaction of the pH-sensitive NR bromomethyl-2,2,3,5,5-pentamethylimidazoline-1-oxyl with aminopropyltriethoxy-silane (APTES) in the presence of trioctylamine and further treatment of the nanostructured SiO2 with the hydrolyzed product and acetic anhydride. It was found that there are two types of location of the pH-sensitive NRs (spin labels) on the surface of nanostructured silica. The spin labels of the first type located near the surface of nanostructured SiO2 (“slow-motional” NR) have been used to measure near-surface electrical potential at the site of NR N–O• fragment location, q equal to −90 mV. The NR molecules of the second type which were positioned well far from the nanostructured SiO2 surface (“fast-motional” NRs) were employed to establish the regularities of mutual changes in the NR form and nanoparticle surface charge with variations in pH of external bulk solution (pHext). The pH-sensitive NRs covalently attached to the SiO2 surface were successfully employed for the study of surface charge in the drying process with a rise of temperature up to 375 K. A negative surface charge was shown to decrease due to reducing an ionization degree of the surface silanol groups. This process was found to be reversible at re-adsorption of water molecules. © 2015, Springer-Verlag Wien.

Our research activities during the last eight years from 2006 to 2013, with the grant supports from Nano National programs, NSC, Taiwan and AOARD, have been pushing the material limits of III-V InGaAs and GaN metal-oxide-semiconductor (MOS) systems using high-k dielectrics. In the third year of the funding, with the capabilities of atomic-scale probing and manipulating the high-k oxides/semiconductors interfaces, we have established the correlations between electronic structures and electrical properties essential to understand the Fermi level pinning/unpinning mechanism of the interfaces between metal/oxide and oxide/semiconductor. we have successfully continuously kept our world-leading expertise of high-k dielectric growth on InGaAs by achieving world record drain current of 1.8 mA/micro m, transconductance of 0.80 mS/micro m, and low sub-thresholds in a self-aligned inversion-channel InGaAs metal-oxide-semiconductor field-effect- transistor of 1 micro m gate length. In-situ ultrahigh vacuum deposited Y2O3 and HfO2 and atomic-layer-deposited (ALD) Al2O3 and HfO2 2-3 mono-layers thick on freshly grown In0.53Ga0.47As, with an Al2O3 cap, were employed as a gate dielectric., Prepared in collaboration with the Department of Physics, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.