ACCESSIBILITY AS A NON-PREJUDICIAL APPROACH: IS CULTURE BACK TO NORMALITY?Ilaria Bollati
, 2018, doktorska disertacija
Opis: This research explores the general and actual accessibility to cultural spaces and organizations, focusing on the network of relationships between contents, innovation, and participation. It investigates how Culture can be perceived as a normal experience, actually able to set a rich dialogue with each of us, normal ordinary people/consumers. Normality means inclusion and sharing. The proposed investigation is based on a triad of interactions among culture, economics, and design.
Assuming that Culture generates its value from a cognitive approach, or from a dynamic and context-dependent value chain that is subject to a cognitive evolution, this research acknowledges that the cultural experience is subject to a double issue of access:
- The horizontal question is related to complications associated with the structure. Believing that ‘culture is special’ implies the risk of progressively widening the gap between cultural supply and society. Culture is ‘locked’ in specific sites and a big slice of the world’s adult population has yet to be involved in any cultural experience.
- Once physically inside the cultural structure, the vertical issue is generated by the difficulty in entering in contact with the offered contents. This research focuses only on museums and multimedia exhibitions in which the learning process has changed: the research presents itself as a conversation where both ‘those who know’ and ‘those who learn’ play equally active parts in a relative process of understanding.
Starting from the existing processes, forms, previous studies and case studies, the survey yearns for their systematization in innovative models. The process, from theory to practice and vice versa, goes beyond a traditional mechanism of deduction: it moves from specific contexts to the abstraction of replicable approaches.
The question of how the narration emerges guides you toward a new method of analysis, study, and cataloguing; a schematization capable of investigating not only knowledge, but also the visitor's ‘cognitive metabolism’ (how knowledge is acquired) during the multimedia experience; an innovative multipurpose tool, useful for both the museum institution and the designer.
The research finally assesses and takes into account an actual experiment, the outcomes of which may prove to be useful in feeding theoretical implications with empirical experiences: RovelloDue - Piccolo Spazio Politecnico, a temporary multimedia space.
Najdeno v: ključnih besedah
Povzetek najdenega: ...emotion, immersion, innovation, interactive exhibitions, participation, natural interfaces, normality, technologies...
Ključne besede: audience development, cognitive accessibility, cultural addiction, culture, human, emotion, immersion, innovation, interactive exhibitions, participation, natural interfaces, normality, technologies
Objavljeno: 13.12.2018; Ogledov: 2565; Prenosov: 40
Polno besedilo (45,89 MB)
Chemical Instability of an Interface between Silver and Bi2Se3 Topological Insulator at Room TemperatureKatja Ferfolja
, Matjaž Valant
, Iuliia Mikulska
, Sandra Gardonio
, Mattia Fanetti
, 2018, izvirni znanstveni članek
Opis: Understanding an interaction at an interface between a topological insulator and a metal is of critical importance when designing electronic and spintronic devices or when such systems are used in catalysis. In this paper, we report on a chemical instability of the interface between Bi2Se3 and Ag studied by X-ray powder diffraction and electron microscopy. We present strong experimental evidence of a redox solid-state reaction occurring at the interface with kinetics that is significant already at room temperature. The reaction yields Ag2Se, AgBiSe2, and Bi. The unexpected room-temperature chemical instability of the interface should be considered for all future theoretical and applicative studies involving the interface between Bi2Se3 and Ag.
Najdeno v: ključnih besedah
Povzetek najdenega: ...topological insulators, Ag, thin metal films, interfaces, redox reaction...
Ključne besede: topological insulators, Ag, thin metal films, interfaces, redox reaction
Objavljeno: 17.06.2020; Ogledov: 1913; Prenosov: 0
Polno besedilo (3,93 MB)
Structural, morphological and chemical properties of metal/topological insulator interfacesKatja Ferfolja
, 2021, doktorska disertacija
Opis: Topological insulators (TIs) represent a new state of matter that possess a different band structure than regular insulators or conductors. They are characterized with a band gap in the bulk and conductive topological states on the surface, which are spin polarized and robust toward contamination or deformation of the surface. Since the intriguing properties of the TIs are localized at the surface, it is important to obtain knowledge of the possible phenomena happening at the interface between TIs and other materials. This is especially true in the case of metals, due to the fact that such interfaces will be present in the majority of foreseen TI applications.
The presented study combines microscopy and spectroscopy techniques for characterization of morphology, stability and chemical interaction at the interface between TI and metals deposited by means of physical vapor deposition. Our research is based on the interface of Bi2Se3 topological insulator with Ag, Ti and Pt – metals that can be encountered in devices or applications predicted to utilize the special properties of topological insulators.
STM and SEM imaging of Ag/Bi2Se3 interface showed that Ag atoms arrange on the surface in the form of islands, whereas significantly bigger agglomerates are found at the surface steps. The interface was found to be unstable in time and resulted in the absorption of the metal into the crystal at room temperature. Evidences of a chemical reaction at the Ag/Bi2Se3 interface are presented, showing that new phases (Ag2Se, AgBiSe2 and metallic Bi) are formed.
Deposition of Ti on Bi2Se3 resulted in different morphologies depending on the film thickness. At a very low coverage (<1 Å) islands are formed. However, the islands growth is hindered before the completion of a full layer due to the occurrence of a chemical reaction. No surface features could be detected by SEM for Ti coverage up to 20 nm. In contrary, when Ti thickness reached 40 nm, compressive stress triggered buckling of the deposited film. XPS analysis revealed that a redox solid-state reaction occurs at the Ti/Bi2Se3 interface at room temperature forming titanium selenides and metallic Bi. The reaction has significant kinetics even at cryogenic temperature of 130 K.
Pt forms a homogenous film over the whole substrate surface, which is stable in time at room temperature. Although the interface of Pt with Bi2Se3 was found to be
less reactive compared to Ag and Ti, an interfacial phase formed upon annealing to ∼90 °C was detected by TEM cross section experiment.
A model for prediction of interfacial reactions between a metal and Bi2Se3 based on the standard reduction potential of the metals and Gibbs free energy for a model reaction is presented. Based on these two values the reaction can be expected to result in the formation of binary and/or ternary selenides and Bi.
Presented work shows on the importance of metal/topological insulator interfaces characterization taking into account the possibility of a chemical reaction with all of its consequences. Results should be considered for future theoretical and applicative studies involving such interfaces as well as for the possible engineering of 2D TI heterostructures.
Najdeno v: ključnih besedah
Ključne besede: topological insulators, topological surface states, Bi2Se3, thin films, Ag, Ti, Pt, morphology, interfaces, solid-state reaction, metal selenides, reactivity, stability, electron microscopy, dissertations
Objavljeno: 09.06.2021; Ogledov: 1790; Prenosov: 123
Polno besedilo (0,00 KB)
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Hot-carrier and optical-phonon ultrafast dynamics in the topological insulator Bi2Te3 upon iron deposition on its surfaceG De Ninno
, K.C. Prince
, M Stupar
, B Ressel
, B Arnaud
, V Juvè
, G Vaudel
, A Ciavardini
, T Sobol
, K Balin
, M Weis
, P Ruello
, J Szade
, 2021, izvirni znanstveni članek
Opis: This paper presents a complete study of electronic structures and photoexcited carrier dynamics in topological insulators capped with iron and iron oxide. We combine static and time-resolved angle-resolved photoemission spectroscopies (ARPES, TR-ARPES) with time-resolved optical methods (transient optical reflectivity and transmission). Both single crystal and thin films of Bi2Te3 are studied. We show that monolayers of iron and iron oxide significantly affect the electronic band structure at the interface by shifting the Fermi level into the conduction band, which we explain by a band bending effect, and is confirmed by in situ XPS measurements
Najdeno v: ključnih besedah
Ključne besede: time resolved spectroscopies, topological insulators, interfaces
Objavljeno: 13.12.2021; Ogledov: 804; Prenosov: 5
Polno besedilo (2,90 MB)