Induced excitations in some metal oxidesSirbu, S. 2008 Groningen: s.n.. 147 p.
Research output: Scientific › Doctoral Thesis
An optical spectrometer may be a tool unfamiliar to an outsider of the optics community. It can be regarded as a natural evolution of the way we perceive the surrounding environment. Light coming from the sun is reflected or transmitted by objects. The human eye, by measuring this reflected or transmitted light, gains some information about the objects themselves, such as their color, brightness, and shape. Using the same principles, an optical spectrometer is designed to gain even more information. It has a source of light used to send light on some objects, and a hi-tech detector to measure the transmitted or reflected light. After the material has been measured, a relation needs to be established between its optical response and its main physical properties. In this thesis we consider the case of solid state materials. These are materials where the atoms are in close proximity to each other, and arranged in repetitive patterns on macroscopic distances, to make a compact structures (a good example is NaCl, kitchen salt). To establish the above mentioned relation the following procedure is followed. First the optical response (transmission, reflectivity, absorption, etc.) at each frequency in the incident light is measured. The result in quantified in terms of the so called dielectric constant of the bulk ε(∞). In a second step, this function is related to the main physical propertied of the measured solid state material, using the knowledge of this particular structure, determined before by different type of measurements, such as for instance X-ray diffraction. Today, optical spectroscopy has become one of the most important standard tools for investigating novel condensed matter materials. The aim of the work presented in this thesis is to investigate the low energy excitation spectra and the (induced) phase transitions in transition metal oxides.
|Qualification||Doctor of Philosophy|
|Place of Publication||Groningen|
|State||Published - 2008|
- Excitonen , Vanadiumoxiden, Metaaloxiden, Europiumoxyde, Kop, spectroscopie, diëlektrische en optische eigenschappen, spectrochemische analyse
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