Browsing by Author "Olaoye, Olufemi Opeyemi"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
- ItemStructural dynamics in DCNQI salts and transition metal dichalcogenides studied by electron diffraction simulation(Stellenbosch : Stellenbosch University, 2015-12) Olaoye, Olufemi Opeyemi; Schwoerer, Heinrich; Stellenbosch University. Faculty of Science. Dept. of Physics.ENGLISH ABSTRACT: An in-depth understanding of the working principles of and phenomena governing strongly correlated condensed matter materials has paved way for technological advancement in electronics in the recent decades. The discovery and characterisation of many functional materials ranging from superconductors to insulators are hinged on the progressive understanding of the driving mechanisms behind macroscopic properties like superconductivity and magneto-resistance. Stemming from the nature of structural transitions in highly correlated solids and the corresponding abrupt changes in their conductivity or resistivity, various degrees of order parameters have been investigated using different experimental techniques such as angle resolved photoelectron spectroscopy, optical reflectivity measurements, X-ray crystallography and pump-probe spectroscopy, among others. One major technique that could be used to gain further understanding of these correlated systems is electron diffraction analysis. In this dissertation, we demonstrate a qualitative working relationship between electron diffraction simulation and the corresponding X-ray and electron diffraction experiments. These structural analysis techniques are used to investigate metal-insulator structural transitions in strong electron-lattice correlated charge density wave compounds of the radical anion organic molecular crystals of Cu-DCNQI and two members of transition metal dichalcogenides, namely, 4Hb-TaSe2 and 1T-TiSe2 single crystals. This study contributes to the observation and dynamics of charge density waves on the atomic spatial and temporal resolutions. A systematic analysis of electron diffraction patterns obtainable from femtosecond electron diffraction experiments opens up new perspectives on the interpretation of structural evolution in solids.