Search for dissertations about: "first-principle calculations"
Showing result 21 - 25 of 38 swedish dissertations containing the words first-principle calculations.
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21. Metastable ScAlN and YAlN Thin Films Grown by Reactive Magnetron Sputter Epitaxy
Abstract : Metastable ScxAl1-xN and YxAl1-xN thin films were deposited in an ultra high vacuum system using reactive magnetron sputter epitaxy from elemental Al, Sc, and Y targets in Ar/N2 gas mixture. Their structural, electrical, optical, mechanical, and piezoelectrical properties were investigated by using the transmission electron microscopy, x-ray diffraction, spectroscopic ellipsometry, I-V and C-V measurements, nanoindentation, and two different techniques for piezoelectric characterization: piezoresponse force microscopy and double beam interferometry. READ MORE
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22. Optical Spectroscopy on Correlated Electron Materials
Abstract : Strongly correlated materials poses a great challenge to our microscopic understanding of matter, mainly due to the inability of perturbative methods to predict the properties of such materials. This inability stems from strong correlations between electronic, lattice and spin degrees of freedom, leading to a variety of complex and exotic phenomena such as (unconventional) superconductivity, metal-insulator transitions, non-Fermi liquid behavior and colossal magnetoresistance. READ MORE
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23. Electronic structure and exchange interactions from ab initio theory : New perspectives and implementations
Abstract : In this thesis, the magnetic properties of several materials were investigated using first principle calculations. The ab initio method named real space linear muffin-tin orbitals atomic sphere approximation (RS-LMTO-ASA) was used to calculate the electronic structure and magnetic properties of bulk systems, surface and nanostructures adsorbed on surfaces. READ MORE
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24. The Influence of Interlayer Exchange Coupling on Magnetic Ordering in Fe-based Heterostructures
Abstract : Temperature dependent magnetization measurements were conducted on Fe-based heterostructures. A linear increase of the magnetic critical temperature with increasing Fe thickness was found for Fe/V superlattices with strong interlayer exchange coupling. READ MORE
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25. Kinetics of collector in-situ adsorption on metal sulphide surfaces studied by ATR-FTIR spectroscopy
Abstract : In sulphide mineral flotation, a sufficient hydrophobicity of the mineral surfaces is obtained by the adsorption of collector chemicals at the metal sulphide/aqueous interface. This surface alteration is of fundamental and applied interest. READ MORE