BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:iCalendar-Ruby BEGIN:VEVENT CATEGORIES:Lectures & Presentations DESCRIPTION:NQPI Nanoforum | Properties of Mn3Sn films grown on sapphire su bstrates using molecular beam epitaxy\, Nov. 3\n\nThe Nanoscale and Quantum Phenomena Institute (NQPI) 's Seminar Forum series features two graduate s tudents in Physics & Astronomy on Nov. 3 at 4:10 p.m. in Walter 245.\n\nSne ha Upadhyay will discuss “Properties of Mn3Sn films grown on sapphire subst rates using molecular beam epitaxy.”\n\n \n\nAbstract: The Kagome antiferro magnet Mn3Sn is a fascinating material because it’s one of the rare antifer romagnets that exhibits large anomalous Hall and Nernst effects. This opens a new area of research using functional antiferromagnets1\, but for future device applications\, it requires fabricating high quality thin films. The re are reports of the controlled growth of Mn3Sn on substrates like m-plane sapphire\,2 Pt/Al2O3 (0001)3 and others using sputtering growth\, but this often can result in polycrystalline films. In this work\, we investigate t he growth of Mn3Sn films on c-plane sapphire substrates using molecular bea m epitaxy. Effusion cells are used for Mn and Sn sources which are calibrat ed using a quartz crystal thickness monitor. The growth is monitored in-sit u using reflection high energy electron diffraction and ex-situ measurement s are carried out using X-ray diffraction\, Rutherford backscattering\, and cross-sectional scanning transmission electron microscopy. The samples are grown at 500 ± 9°C and 416 ± 9 °C with a Mn: Sn atomic flux ratio of 3.2: 1 on c-plane sapphire substrates for 60 mins. We observe streaky RHEED patt erns at both temperatures indicating high quality crystalline growth with 2 different orientations\, (0001) and (11-20)\, which is also backed up by t he XRD spectra. STEM verifies ~3:1 Mn to Sn stoichiometry but also reveals discontiguous films. After optimizing the growth conditions\, the next phas e of the study is to begin in-situ scanning tunneling microscopy and spin-p olarized STM studies of the structural\, electronic\, and magnetic properti es of the as-grown Mn3Sn surfaces\, and in this presentation\, we plan to p resent initial results.\n\n \n\nChinonso Ugwumadu will discuss “Atomistic N ature of Amorphous Layered Carbon Solids.”\n\n \n\nAbstract: Carbon’s (C) s trong proclivity to form layers was observed in the disorder-order transiti on from random configurations of carbon atoms to layered carbon allotropes using GAP machine learning (ML) interatomic potential [1]. Three amorphous structures\, graphite (a-G)\, fullerenes (a-F) and nanotubes (a-NT)\, with pentagons and heptagons in the hexagonal network\, formed from NVT simulati on near 3000K. The formation of these structures is strongly dependent on t he type of periodic boundary condition (PBC) applied. The ring disorder in the C network was found to be combinations of Stone-Wales and (Inverse) Sto ne-Thrower-Wales and Stone-Wales defects. Inter-layer cohesion is partly du e to interaction between delocalized π electrons into the gallery. The impa ct of structural disorder in electronic transport was studied. The Vibratio nal density of states for all the structures was computed and it is potenti ally an experimentally testable fingerprint of the materials. DTEND:20221103T211000Z DTSTAMP:20241123T070020Z DTSTART:20221103T201000Z GEO:39.322732;-82.10287 LOCATION:Walter Hall\, 245 SEQUENCE:0 SUMMARY:NQPI Nanoforum | Chinonso Ugwumadu and Sneha Upadhyay\, Nov. 3 UID:tag:localist.com\,2008:EventInstance_40687378434400 URL:https://calendar.ohio.edu/event/nqpi_seminar_nov_3 END:VEVENT END:VCALENDAR