\"The oxidation kinetics of polycrystalline SrTiO3 and LaCrO3 were determined by measuring the time and temperature dependence of the weight and conductivity change of reduced samples. A region of fast diffusion followed by a reduced diffusion tail was observed in the TGA measurements. This observation can be interpreted as the initial diffusion along the boundaries and then spreading out into the lattice. The absence of the tail in the conductivity measurements is due to the high electron and hole mobility at the boundaries. The electrical conductivity and TGA results on Nb-doped LaCrO3 show that at low oxygen activity the material is a n-type conductor and as oxygen activity increases changes to a p-type conductor. This is consistent with a defect structure whose majority defects at low oxygen activity are electrons due to the donor; at high oxygen activity the increase of hole concentration due to the native oxygen excess nonstoichiometry of the oxide with its higher hole mobility results in p-type conduction. The experimental results also indicate that the electron mobility in this material is about 0.002 cm2/V-sec at 1200 °C\"\"--Abstract, p. ii
","abstract_html":"<p>"The oxidation kinetics of polycrystalline SrTiO<sub>3</sub> and LaCrO<sub>3</sub> were determined by measuring the time and temperature dependence of the weight and conductivity change of reduced samples. A region of fast diffusion followed by a reduced diffusion tail was observed in the TGA measurements. This observation can be interpreted as the initial diffusion along the boundaries and then spreading out into the lattice. The absence of the tail in the conductivity measurements is due to the high electron and hole mobility at the boundaries. The electrical conductivity and TGA results on Nb-doped LaCrO<sub>3</sub> show that at low oxygen activity the material is a n-type conductor and as oxygen activity increases changes to a p-type conductor. This is consistent with a defect structure whose majority defects at low oxygen activity are electrons due to the donor; at high oxygen activity the increase of hole concentration due to the native oxygen excess nonstoichiometry of the oxide with its higher hole mobility results in p-type conduction. The experimental results also indicate that the electron mobility in this material is about 0.002 cm<sup>2</sup>/V-sec at 1200 °C""--Abstract, p. ii</p>","abstract_has_math":false,"creators":["Yu, Chi-Kung Jerry"],"institution":"University of Missouri--Rolla","degree_name":"Ph. D. in Ceramic Engineering","degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-02-10T08:00:00Z","date_published":"2016-02-10T08:00:00Z","updated_at":"2026-07-24T03:18:09Z","subjects":["Ceramic Materials"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsmine.mst.edu/doctoral_dissertations/608","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Yu, Chi-Kung Jerry"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2016-02-10T08:00:00Z"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation - Open Access"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. D. in Ceramic Engineering"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Missouri--Rolla"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Ceramic Materials"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarsmine.mst.edu/doctoral_dissertations/608"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["\"The oxidation kinetics of polycrystalline SrTiO3 and LaCrO3 were determined by measuring the time and temperature dependence of the weight and conductivity change of reduced samples. A region of fast diffusion followed by a reduced diffusion tail was observed in the TGA measurements. This observation can be interpreted as the initial diffusion along the boundaries and then spreading out into the lattice. The absence of the tail in the conductivity measurements is due to the high electron and hole mobility at the boundaries. The electrical conductivity and TGA results on Nb-doped LaCrO3 show that at low oxygen activity the material is a n-type conductor and as oxygen activity increases changes to a p-type conductor. This is consistent with a defect structure whose majority defects at low oxygen activity are electrons due to the donor; at high oxygen activity the increase of hole concentration due to the native oxygen excess nonstoichiometry of the oxide with its higher hole mobility results in p-type conduction. The experimental results also indicate that the electron mobility in this material is about 0.002 cm2/V-sec at 1200 °C\"\"--Abstract, p. ii
"]},{"key":"dc:title","label":"Title","values":["Oxidation kinetics of polycrystalline SrTiO₃ and LaCrO₃"]}]}],"canonical_facts":{"dc:creator":["Yu, Chi-Kung Jerry"],"dc:date.available":["2016-02-10T08:00:00Z"],"dc:description.abstract":["\"The oxidation kinetics of polycrystalline SrTiO3 and LaCrO3 were determined by measuring the time and temperature dependence of the weight and conductivity change of reduced samples. A region of fast diffusion followed by a reduced diffusion tail was observed in the TGA measurements. This observation can be interpreted as the initial diffusion along the boundaries and then spreading out into the lattice. The absence of the tail in the conductivity measurements is due to the high electron and hole mobility at the boundaries. The electrical conductivity and TGA results on Nb-doped LaCrO3 show that at low oxygen activity the material is a n-type conductor and as oxygen activity increases changes to a p-type conductor. This is consistent with a defect structure whose majority defects at low oxygen activity are electrons due to the donor; at high oxygen activity the increase of hole concentration due to the native oxygen excess nonstoichiometry of the oxide with its higher hole mobility results in p-type conduction. The experimental results also indicate that the electron mobility in this material is about 0.002 cm2/V-sec at 1200 °C\"\"--Abstract, p. ii
"],"dc:identifier":["https://scholarsmine.mst.edu/doctoral_dissertations/608"],"dc:subject":["Ceramic Materials"],"dc:title":["Oxidation kinetics of polycrystalline SrTiO₃ and LaCrO₃"],"dc:type":["Dissertation - Open Access"],"thesis:degree_name":["Ph. D. in Ceramic Engineering"],"thesis:institution_name":["University of Missouri--Rolla"]},"updated_at":"2026-07-24T03:18:09Z"}