Repository of University of Nova Gorica

Search the repository
A+ | A- | Help | SLO | ENG

Query: search in
search in
search in
search in
* old and bologna study programme

Options:
  Reset


1 - 6 / 6
First pagePrevious page1Next pageLast page
1.
Room-temperature solid-state reaction at the Ag/Bi[sub]2Se[sub]3 interface
Katja Ferfolja, Mattia Fanetti, Iuliia Mikulska, Sandra Gardonio, Matjaž Valant, 2017, published scientific conference contribution abstract

Abstract: Topological insulators (TI) are materials that, while having a forbidden bandgap in bulk, are conductors at their surface due to presence of surface-localized electronic states crossing the band gap. [1] TIs are possible because of a time reversal symmetry and spin-orbit coupling, which invert bulk band states in their energy positions and make the bulk band structure non trivial. Consequently, the topological surface states (TSS) emerge on the surface of these materials. Unlike ordinary surface states, TSS cannot be destroyed by contamination or defects on the surface. Additionally, TSS are also spin polarized, which means that when applying current to TI, the current will have a well defined direction of the electron spins. The topological insulators - a relatively new class of materials - are being widely studied not only from fundamental aspects, but also from their applicative perspectives. It has been predicted that TIs could be used in fields of spintronics, electronics and catalysis. [2,3] Interestingly, only a few studies about metal/TI interfaces have been reported. This is surprising since integration of TI in the applications will often necessitate an interface with the metal, therefore, detailed knowledge on chemistry and electrical conditions at the interface will be required. In this contribution results on research on the chemistry of the Ag/Bi2Se interface will be presented, in particularonthesolid-statereactionbetweennanoparticles.IthasbeenobservedthatwhenBi2Se3 andAgare put in contact a chemical reaction occurs at the interface, producing AgBiSe2 and Ag2Se. Interestingly, the reaction already occurs at room temperature, which is not usual for solid-state reactions. In literature this reaction has not been properly described. The authors rather described it as intercalation of the silver atoms, which we have disproved and showed that recrystallization of the new phases occurs. [3,4,5] The results will alsobediscussedincomparisonwithothertwoAg/Bi2Se3 systemsunderourinvestigation:i)Agdepositedby achemicalrouteonBi2Se3 nanoflakesandii)AgdepositedfromavapourphaseinvacuumonaBi2Se3.single crystal
Keywords: topological insulators, topological surface states, solid-state reaction, TI/metal interface
Published in RUNG: 20.08.2021; Views: 2137; Downloads: 0
This document has many files! More...

2.
Chemical Instability of an Interface between Silver and Bi2Se3 Topological Insulator at Room Temperature
Katja Ferfolja, Matjaž Valant, Iuliia Mikulska, Sandra Gardonio, Mattia Fanetti, 2018, original scientific article

Abstract: 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.
Keywords: topological insulators, Ag, thin metal films, interfaces, redox reaction
Published in RUNG: 17.06.2020; Views: 2981; Downloads: 0
This document has many files! More...

3.
4.
5.
Structural and magnetic properties of Fe-doped BaTiO [sub] 3 ceramics : dissertation
Iuliia Mikulska, 2014, doctoral dissertation

Keywords: barijev titanat, kisikova vrzel, Fe rob K EXAFS, XANES, disertacije
Published in RUNG: 22.01.2015; Views: 6106; Downloads: 371
URL Link to full text
This document has many files! More...

6.
Search done in 0.04 sec.
Back to top