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| Author(s): |
Matheus Henry Przygocki
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Física (IF/SBI) |
| Defense date: | 2022-07-21 |
| Examining board members: |
Julio Antonio Larrea Jimenez;
Izabel Fernanda Machado;
Marcello Barbosa da Silva Neto
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| Advisor: | Julio Antonio Larrea Jimenez |
| Abstract | |
This work presents an investigation of structural, microstructural, electrical and thermal transport properties of two-dimensional SrTiO3 and FeGa3 under the effect of different thin film preparation methods. Besides, new proposals of home-built experimental platforms are presented as routes to realize the measurements of collective quantum phenomena in bulk and thin film samples not currently available commercially. For the case of the insulator SrTiO3, a controlled atomic growth layer by layer is realized by Molecular Beam Epitaxy (MBE) to produce ultrathin films with thickness in the order of few nanomometers. A comparative analysis of our x-ray diffraction (XRD) data between bulk and ultrathin film of SrTiO3 revealed an epitaxial growth along the (002) crystallographic direction, along with an unusual thickness dependence of the grain size and microdeformation of the crystal structure, both quantities decreasing with thickness. We ascribed these atypical results to the competition between bulk and surface effects arise from sample preparation-thin film growth. On the other hand, the bulk semiconductor FeGa3 was grown as thin film with rf-sputtering method. An investigation as function of temperature, time and atmosphere annealing conditions post as-cast thin film deposition is also realized. By analyzing the XRD, we manage to characterize that amorphous as-cast thin film can reach crystalline structure at optimal annealing conditions which depends on the thin film thickness we want to reach. Very interesting is the observation of some crystalline texture of the thin films along the planes (112) and (004) which does not depend on the thin film thickness. Finally, we also show a discussion of proposal of home-built platforms to measure specific heat and thermal conductivity of our samples using methods with applied alternate (AC) and continue (DC) power excitations. In addition, a prototype of Conversion Electron Mössbauer Spectroscopy (CEMS) detector to investigate the magnetic and electronic interaction in our thin films is also presented. We expect that the results of this thesis contributes with relevant information about the sample characterization and show feasible routes to set new experimental methods to investigate correlated quantum phenomena with the resolution not commercially available so far. (AU) | |
| FAPESP's process: | 19/24687-1 - Investigation of collective quantum phenomena in low-dimensional systems |
| Grantee: | Matheus Henry Przygocki |
| Support Opportunities: | Scholarships in Brazil - Master |