Search results for "kalvot"

A Computational Study of Adsorption of CO2, SO2, and H2CO on Free-Standing and Molybdenum-Supported CaO Films

2019

Oxide films play a significant role in a wide range of fields from catalysis to solar cell materials. CaO films are promising sorbents for many environmentally harmful molecules. Here, we report a systematic investigation of adsorption of CO2, SO2, and H2CO on bulk and Mo-supported CaO(100) films using density functional theory. Significant effects on adsorption energy, charge transfer to the molecules, and degree of the C−O bond activation were demonstrated on Mo-supported CaO films by changing the film thickness, composition, and the strength and direction of an applied external electric field. These findings are relevant for interpreting results from scanning tunneling microscopy of smal…

Clustering-triggered endocytic pathway of α2β1 integrin

2012

Interactions of α2β1 integrin and its ligands, type I collagen and echovirus 1

2015

Itsekantavien hiilinanoputkivahvisteisten alumiinioksidikalvojen valmistus ja karakterisointi

2016

Tässä pro gradu -tutkielmassa pyrittiin valmistamaan hiilinanoputkilla vahvistettuja itsekantavia Al2O3-ohutkalvoja. Ohutkalvot kasvatettiin märkäetsauksella ja atomikerroskasvatuksella ja niitä vahvistettiin levittämällä hiilinanoputkia Al2O3-kerrosten väliin. Hiilinanoputkia linkitettiin verkostomaiseksi rakenteeksi ionisäteilytyksellä. Kalvoja karakterisoitiin valmistuksen aikana ja sen jälkeen elektronimikroskopialla, atomivoimamikroskopialla, profilometrialla ja ramanspektroskopialla. Käytettyjen karakterisointimenetelmien perusteella hiilinanoputkien linkittymistä saattoi olla havaittavissa. Hiilinanoputkilla vahvistettujen itsekantavien Al2O3-kalvojen Youngin moduulin arvoksi saatiin…

Atomic Layer Deposition of Intermetallic Fe4Zn9 Thin Films from Diethyl Zinc

2022

| openaire: EC/H2020/765378/EU//HYCOAT We present a new type of atomic layer deposition (ALD) process for intermetallic thin films, where diethyl zinc (DEZ) serves as a coreactant. In our proof-of-concept study, FeCl3 is used as the second precursor. The FeCl3 + DEZ process yields in situ crystalline Fe4Zn9 thin films, where the elemental purity and Fe/Zn ratio are confirmed by time-of-flight elastic recoil detection analysis (TOF-ERDA), Rutherford backscattering spectrometry (RBS), atomic absorption spectroscopy (AAS), and energy-dispersive X-ray spectroscopy (EDX) analyses. The film thickness is precisely controlled by the number of precursor supply cycles, as expected for an ALD process.…

Computational studies of gold-absorbate complexes on modified oxides

2016

While bulk gold is known for its chemical inertness, nanosized gold clusters are active catalysts for a variety of important reactions. For some practical applications gold clusters are supported and the cluster-support interaction can modify the cluster's properties. The knowledge of this interaction can be vital for obtaining desired cluster properties. In this thesis, the adsorption of Au atoms and clusters on modified oxide surfaces is studied using density functional theory (DFT) calculations. The support effects are considered by direct analysis of the adsorbed Au and using other coadsorbates as reactivity probes. Doping the CaO(001) surface by replacing a cation with a high valence d…

Deterministic Modification of CVD Grown Monolayer MoS2 with Optical Pulses

2021

| openaire: EC/H2020/820423/EU//S2QUIP | openaire: EC/H2020/834742/EU//ATOP Transition metal dichalcogenide monolayers have demonstrated a number of exquisite optical and electrical properties. Here, the authors report the optical modification of topographical and optical properties of monolayer MoS2 with femtosecond pulses under an inert atmosphere. A formation of three-dimensional structures on monolayer MoS2 with tunable height up to ≈20 nm is demonstrated. In contrast to unmodified monolayer MoS2, these optically modified structures show significantly different optical properties, such as lower photoluminescence intensity and longer fluorescence lifetime. The results suggest a novel way…

Tribological properties of thin films made by atomic layer deposition sliding against silicon

2018

Interfacial phenomena, such as adhesion, friction, and wear, can dominate the performance and reliability of microelectromechanical (MEMS) devices. Here, thin films made by atomic layer deposition (ALD) were tested for their tribological properties. Tribological tests were carried out with silicon counterpart sliding against ALD thin films in order to simulate the contacts occurring in the MEMS devices. The counterpart was sliding in a linear reciprocating motion against the ALD films with the total sliding distances of 5 and 20 m. Al2O3 and TiO2 coatings with different deposition temperatures were investigated in addition to Al2O3-TiO2-nanolaminate, TiN, NbN, TiAlCN, a-C:H [diamondlike car…

Al2O3 ALD films grown using TMA + rare isotope 2H216O and 1H218O precursors

2021

In this work hydrogen and oxygen migration and exchange reactions in the atomic layer deposited (ALD) Al2O3 thin films were studied together with hydrogen incorporation by varying deposition parameters. Al2O3 films deposited at low temperatures can contain more than 20 at. % of hydrogen. Both higher temperature and longer purge length decrease the hydrogen and carbon concentrations significantly. In order to track the hydrogen and oxygen movement in the films, heavy water (2H216O) and oxygen-18 enriched water (1H218O) were used as precursors in combination with trimethylaluminium (TMA). Different isotopes of the same element were quantified by means of time-of-flight elastic recoil detectio…

Specific heat of thin phonon cavities at low temperature: Very high values revealed by zeptojoule calorimetry

2022

The specific heat of phonon cavities is investigated in order to analyze the effect of phonon confinement on thermodynamic properties. The specific heat of freestanding very thin SiN membranes in the low-dimensional limit is measured down to very low temperatures (from 6 K to 50 mK). In the whole temperature range, we measured an excess specific heat orders of magnitude bigger than the typical value observed in amorphous solids. Below 1 K, a crossover in cp to a lower power law is seen, and the value of the specific heat of thinner membranes becomes larger than that of thicker ones demonstrating a significant contribution coming from the surface. We show that this high value of the specific…