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Ultrafast electron diffraction on the charge density wave compound 4Hb-TaSe2

Thesis (MSc)--Stellenbosch University, 2012.

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Main Author: Boshoff, Ilana
Other Authors: Schwoerer, Heinrich
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2012
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access_status_str Open Access
author Boshoff, Ilana
author2 Schwoerer, Heinrich
author_browse Boshoff, Ilana
Schwoerer, Heinrich
author_facet Schwoerer, Heinrich
Boshoff, Ilana
author_sort Boshoff, Ilana
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (MSc)--Stellenbosch University, 2012.
format Thesis
id oai:scholar.sun.ac.za:10019.1/20062
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:46:36.532Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2012
publishDateRange 2012
publishDateSort 2012
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/20062 Ultrafast electron diffraction on the charge density wave compound 4Hb-TaSe2 Boshoff, Ilana Schwoerer, Heinrich Rohwer, Erich G. Stellenbosch University. Faculty of Science. Dept. of Physics. Ultrafast electron diffraction Charge density wave Tantalumdiselenite Dissertations -- Physics Theses -- Physics Laser plasma-based ultrafast x-ray source Apparatus Thesis (MSc)--Stellenbosch University, 2012. ENGLISH ABSTRACT: Ultrafast electron diffraction is a powerful method to study atomic movement in crystals on sub-picosecond timescales. This thesis consists of three parts. In part one the ultrafast electron diffraction machine is described, followed by improvements that were made and techniques that were developed in order to bring the system to state of the art level and enable the acquisition of suffcient data to obtain information on the structural dynamics in crystals. The second part contains a description of the sample which was studied in our fi rst time-resolved measurements, the transition-metal dichalcogenide 4Hb-TaSe2. This particular crystal is an example of a strongly coupled electronic system which develops a charge density wave (CDW) accompanied by a periodic lattice distortion (PLD). An overview of the formation of electron diffraction patterns and what can be learned from them are also given, followed by the results of the ultrafast electron diffraction experiments done with 4Hb-TaSe2. Part three describes an alternative source to study dynamics in crystalline samples, namely laser plasma-based ultrafast X-ray diffraction. The ultrafast electron diffraction group functions as a unit, but my tasks ranged from sample preparation and characterisation of the electron beam to the setting up and execution of experiments. I was involved in analysing the data and contributed small parts to the data analysis software. AFRIKAANSE OPSOMMING: Ultravinnige elektron diffraksie is a metode om die beweging van atome in kristalle op sub-pikosekonde tydskale te bestudeer. Hierdie tesis bestaan uit drie dele. In deel een van die tesis word die ultravinnige elektron diffraksie masjien beskryf, gevolg deur verbeteringe wat aangebring is en tegnieke wat ontwikkel is om die sisteem tot op 'n wêreldklas vlak te bring waar die insameling van genoegsame data om inligting oor die strukturele dinamika in kristalle te bekom, moontlik is. Die tweede deel bevat 'n beskrywing van die monster wat in ons eerste tydopgeloste eksperimente gebruik is, naamlik die oorgangsmetaaldichalkogenied 4Hb-TaSe2. Hierdie kristal is 'n voorbeeld van 'n sterk gekoppelde elektroniese sisteem wat 'n ladingsdigtheid-golf en 'n gepaardgaande periodiese versteuring van die kristalrooster ontwikkel. 'n Oorsig van die formasie van elektron diffraksiepatrone en wat ons daaruit kan leer word ook gegee. Daarna word die resultate van die ultravinnige elektron diffraksie eksperimente wat op 4Hb-TaSe2uitgevoer is beskryf en bespreek. In deel drie word 'n alternatiewe metode om die dinamika in kristalmonsters te bestudeer, naamlik laser plasma-gebaseerde ultravinnige X-straal diffraksie, beskryf. Die ultravinnige elektron diffraksie groep funksioneer as 'n eenheid, maar my verantwoordelikhede het gestrek van die voorbereiding van monsters en die karakterisering van die elektron bundel tot die opstel en uitvoer van eksperimente. Ek was ook betrokke by die analisering van data en het dele van die data analise sagteware geskryf. 2012-03-08T10:57:22Z 2012-03-30T10:38:55Z 2012-03-08T10:57:22Z 2012-03-30T10:38:55Z 2012-03 Thesis http://hdl.handle.net/10019.1/20062 en_ZA Stellenbosch University 56 p. : ill. application/pdf Stellenbosch : Stellenbosch University
spellingShingle Ultrafast electron diffraction
Charge density wave
Tantalumdiselenite
Dissertations -- Physics
Theses -- Physics
Laser plasma-based ultrafast x-ray source
Apparatus
Boshoff, Ilana
Ultrafast electron diffraction on the charge density wave compound 4Hb-TaSe2
title Ultrafast electron diffraction on the charge density wave compound 4Hb-TaSe2
title_full Ultrafast electron diffraction on the charge density wave compound 4Hb-TaSe2
title_fullStr Ultrafast electron diffraction on the charge density wave compound 4Hb-TaSe2
title_full_unstemmed Ultrafast electron diffraction on the charge density wave compound 4Hb-TaSe2
title_short Ultrafast electron diffraction on the charge density wave compound 4Hb-TaSe2
title_sort ultrafast electron diffraction on the charge density wave compound 4hb tase2
topic Ultrafast electron diffraction
Charge density wave
Tantalumdiselenite
Dissertations -- Physics
Theses -- Physics
Laser plasma-based ultrafast x-ray source
Apparatus
url http://hdl.handle.net/10019.1/20062
work_keys_str_mv AT boshoffilana ultrafastelectrondiffractiononthechargedensitywavecompound4hbtase2