Počet záznamů: 1
Ultralow Energy Scanning Transmission Electron Microscopy and Graphene
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SYSNO ASEP 0481337 Druh ASEP A - Abstrakt Zařazení RIV Záznam nebyl označen do RIV Zařazení RIV Není vybrán druh dokumentu Název Ultralow Energy Scanning Transmission Electron Microscopy and Graphene Tvůrce(i) Frank, Luděk (UPT-D) RID, SAI, ORCID
Mikmeková, Eliška (UPT-D) RIDCelkový počet autorů 2 Zdroj.dok. BIT's 5th Annual Conference of AnalytiX-2017. Conference Abstract Book. - Dalian : BIT Goup Global, 2017
S. 223Poč.str. 1 s. Forma vydání Tištěná - P Akce BIT's Annual Conference of AnalytiX-2017 /5./ Datum konání 22.03.2017 - 24.03.2017 Místo konání Fukuoka Země JP - Japonsko Typ akce WRD Jazyk dok. eng - angličtina Země vyd. CN - Čína Klíč. slova STEM ; graphene ; ulatralow energy Vědní obor RIV JA - Elektronika a optoelektronika, elektrotechnika Obor OECD Nano-materials (production and properties) Institucionální podpora UPT-D - RVO:68081731 Anotace Over the last decade, even commercially available scanning electron microscopes have employed biasing of the specimen to a high negative potential in order to reduce the landing energy of the illuminating electron beam without deteriorating the image resolution. In this way, the electron energy can be lowered to tens or even units of eV provided facilities are available to align the electrostatic field properly above the specimen. Having the specimen sufficiently thin and therefore penetrable for ultralow energy electrons, we can also implement STEM at these energies by inserting the detector at ground potential below the biased sample. Pilot experiments have verified the performance of ultralow energy STEM on very thin tissue sections not treated with any agents containing heavy metals and on 2D crystals, including graphene. Greatly enhanced intensity of interaction of ultraslow electrons with solids produces very high image signals, even for light elements constituting living matter or for differences in thickness amounting to one atomic layer of carbon. This has enabled us to measure transmissivity for electrons from 0 to 40 eV in dependence of the number of graphene layers. Moreover, we have examined phenomena occurring on surfaces bombarded with very slow electrons under various vacuum conditions in order to compare them with traditional carbonaceous contamination of electron-illuminated surfaces in a standard vacuum. We found slow electrons releasing hydrocarbon molecules instead of decomposing them, resulting in much cleaner surfaces securing the increasing transmissivity of graphene. We have established a range of electron energies not generating local defects in the graphene lattice by means of Raman spectroscopy. Pracoviště Ústav přístrojové techniky Kontakt Martina Šillerová, sillerova@ISIBrno.Cz, Tel.: 541 514 178 Rok sběru 2018
Počet záznamů: 1