Theoretical description of magnetic Compton scattering and magnetic properties of Cr-chalcogenide compounds

Benea, Diana Ancuta (2004): Theoretical description of magnetic Compton scattering and magnetic properties of Cr-chalcogenide compounds. Dissertation, LMU München: Fakultät für Chemie und Pharmazie

Abstract

The subject of this work was to use the SPR-KKR formalism to investigate the ground state properties of materials from Cr-chalcogenide class and to describe the spectroscopic properties (Compton scattering and possitron annihilation) of different metallic systems. The fundamentals of the theoretical approach applied is presented in Chapter 2. In particular, the basics of the density functional theory used to reduce the many body electron-electron interaction to single electrons moving independently in an effective potential, together with the SPR-KKR formalism used to solve the electronic structure problem are discussed in detail. This theoretical formalism is applied to get the description of the magnetic Compton profile, as it is shown in Chapter 3, together with the results for pure metals, alloys and ordered compounds. The formalism which describe the positron annihilation os presented in Chapter 4. The 2D projection of the electron-positron momentum density for V it was compared with the experimental spectra and with the LMTO calculated spectra. A complementary approach to investigate the magnetic behaviour of solids using a microscopic model of the magnetic interaction was combined with the SPR-KKR band structure calculations in order to determine the magnetic ground state of CrSe and CrTe systems. The influence of the exchange-correlation treatment on the equilibrium lattice parameters for CrSexTe1-x alloy was investigated. The magnetic moments and density of states for Cr5Te8 system substituted with Se and Ti have been investigated, as can be seen in Chapter 5.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Keywords: DFT, KKR, magnetic Compton profile, positron annihilation, 2D-ACAR, Cr chalcogenide, magnetic moments, density of states
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie ; 500 Naturwissenschaften und Mathematik
• Fakultäten: Fakultät für Chemie und Pharmazie
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 10. Dezember 2004
• 1. Bericht­erstatter:in: Ebert, Hubert