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Australian Institute for Innovative Materials - Papers

2011

Diffusion

Articles 1 - 2 of 2

Full-Text Articles in Engineering

In-Field Jc Improvement By Oxygen-Free Pyrene Gas Diffusion Into Highly Dense Mgb2 Superconductor, Minoru Maeda, Jung Ho Kim, Y Zhao, Yoon-Uk Heo, K Takase, Y Kubota, C Moriyoshi, F Yoshida, Y Kuroiwa, S X. Dou Jan 2011

In-Field Jc Improvement By Oxygen-Free Pyrene Gas Diffusion Into Highly Dense Mgb2 Superconductor, Minoru Maeda, Jung Ho Kim, Y Zhao, Yoon-Uk Heo, K Takase, Y Kubota, C Moriyoshi, F Yoshida, Y Kuroiwa, S X. Dou

Australian Institute for Innovative Materials - Papers

Oxygen-free pyrene gas as a carbon (C) dopant was delinked and incorporated into highly dense MgB2 structure via a gas phase diffusion method. The technique offers the advantages that molecular C is homogeneously distributed into MgB2 and substituted at the boron sites without any severe deterioration of grain connectivity. The C substitution causes a significant shrinkage of the a-lattice parameter and an increase in the lattice strain, resulting in high disorder. The introduction of structural disorder as a result of C doping leads to a considerable enhancement of the in-field critical current density (Jc) and upper critical …


Position Preference And Diffusion Path Of An Oxygen Ion In Apatite-Type Lanthanum Silicate La9.33si6o26: A Density Functional Study, Ting Liao, Taizo Sasaki, Shigeru Suehara, Ziqi Sun Jan 2011

Position Preference And Diffusion Path Of An Oxygen Ion In Apatite-Type Lanthanum Silicate La9.33si6o26: A Density Functional Study, Ting Liao, Taizo Sasaki, Shigeru Suehara, Ziqi Sun

Australian Institute for Innovative Materials - Papers

Using density functional theory, we investigated the position preference and diffusion mechanisms of interstitial oxygen ions in lanthanum silicate La9.33Si6O26, which is an apatite-structured oxide and a promising candidate electrolyte material for solid oxide fuel cells. The reported lanthanum vacancies were explicitly taken into account by theoretically determining their arrangement with a supercell model. The most stable structures and the formation energies of oxygen interstitials were determined for each charged state. It was found that the double-negatively charged state is stable over a wide range of the Fermi level, and that the excess oxygen …