TY - THES

T1 - Preparation and 3D – characterization of porous BaTiO3

AU - Wieser, Philipp Aldo

N1 - no embargo

PY - 2019

Y1 - 2019

N2 - The aim of this work was to produce porous BaTiO3 ceramics with defined porosity and pore morphology for application as dielectrics/ferroelectrics. The porosity was designed via the so-called pore forming method, which includes the mixing of the ceramic powder with a pore former. The pore former is then burned out in the sintering process, yielding pores in the ceramic. To attain different pore morphologies and porosity two different types of pore formers were added to the BaTiO3, namely graphite and corn starch. In addition, the pore former content was varied. The resulting microstructure was analysed using 2D and 3D imaging methods. A chemical analysis was performed via RAMAN spectroscopy. Conclusion: -The analysis of the pore structure in 3D led to a clear distinction of the pore morphology, i.e. pore size and shape, of the samples. -Samples produced with graphite had more elongated pores than samples produced with corn starch. -The morphology was also influenced by adding a pore former or changing the mixing medium. Both led to higher pore sizes and less elongated pores in the samples produced with graphite. -The porosity of the samples increased with the amount of the pore former. -The analysis of the RAMAN spectra provides information regarding the orthorhombic phase. -Changing the pore former did not affect the chemical composition of the samples.

AB - The aim of this work was to produce porous BaTiO3 ceramics with defined porosity and pore morphology for application as dielectrics/ferroelectrics. The porosity was designed via the so-called pore forming method, which includes the mixing of the ceramic powder with a pore former. The pore former is then burned out in the sintering process, yielding pores in the ceramic. To attain different pore morphologies and porosity two different types of pore formers were added to the BaTiO3, namely graphite and corn starch. In addition, the pore former content was varied. The resulting microstructure was analysed using 2D and 3D imaging methods. A chemical analysis was performed via RAMAN spectroscopy. Conclusion: -The analysis of the pore structure in 3D led to a clear distinction of the pore morphology, i.e. pore size and shape, of the samples. -Samples produced with graphite had more elongated pores than samples produced with corn starch. -The morphology was also influenced by adding a pore former or changing the mixing medium. Both led to higher pore sizes and less elongated pores in the samples produced with graphite. -The porosity of the samples increased with the amount of the pore former. -The analysis of the RAMAN spectra provides information regarding the orthorhombic phase. -Changing the pore former did not affect the chemical composition of the samples.

KW - poröse Keramiken

KW - BaTiO3

KW - 3D-Charakterisierung

KW - RAMAN

KW - Poreforming

KW - Graphit

KW - Maisstärke

KW - Porenmorphologie

KW - Porengröße

KW - 3D-characterization

KW - processing of porous ceramics

KW - BaTiO3

KW - pore morphology

KW - pore size

KW - pore forming method

KW - graphite

KW - corn starch

KW - RAMAN

M3 - Master's Thesis

ER -