Oxidation kinetics of polycrystalline SrTiO₃ and LaCrO₃

<p>"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</p>

Name thesis:degree_name

Ph. D. in Ceramic Engineering

Grantor

University of Missouri--Rolla

Year dc:date.available

2016

Author dc:creator

• Yu, Chi-Kung Jerry

• Ceramic Materials

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/608

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-1610