| Description |
vii, 129 leaves : illustrations ; 29 cm |
| Summary |
"The development of the tensi-volumetric apparatus has been traced to its current position of significance in studies relating to oxide non-stoichiometry. Components of the tensi-volumetric apparatus, especially the capacitance membrane manometer, were examined in detail as were the parameters affecting the performance of such an apparatus. Based on a careful consideration of components and performance, a tensi-volumetric apparatus has been designed, built, and its operation theoretically justified for its particular physical configuration. Results of existing studies of the oxygen non-stoichiometry of barium titanate have been used to predict its behavior during a tensi-volumetric study. Specific analytical procedures developed for use with the present tensi-volurnetric system were applied to pure, polycrystalline barium titanate powder at 900°C over the pressure range 10⁻⁴ mm Hg to 740 mm Hg in a pure oxygen atmosphere. Results of the application of these procedures exhibit a p-n transition in the region of 1 mm Hg. The maximum oxygen non-stoichiometry at 900°C and 3 mm Hg was found to correspond to BaTiO[subscript 3+delta] where [delta] = 1.1 x 10⁻⁵ . The diffusion coefficient for the predominent diffusing species on the p side of the transition was found to equal 1.9 x 10⁻¹⁵ cm²/sec. These results and the performance of the system are discussed"--Abstract, leaf ii. |
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