New comprehensive defect-crystal-chemistry approach to defect-fluorite oxides-(m1-yLny)O2-y/2 (M4+=Zr, Hf, Ce and Th etc, Ln3+=lanthanide)

International Conference and Expo on Ceramics

August 17-18, 2015 Chicago, USA

Akio Nakamura

Scientific Tracks Abstracts: J Material Sci Eng

Abstract :

This presentation describes the recently proposed a new comprehensive defect-crystal-chemistry approach as a possible unified
generalized Vegard-Law (VL) description of non-Vegardianity and non-random defect structure of entitled so-called defectfluorite
oxides as inherently coupled two sides of distortion-dilation in macroscopic lattice parameter and microscopic ionic
radius level, respectively. It provides a new direct link to their controversial defect structure and its dependent key basic as well
as engineering properties such as oxide-ion conductivity (σ(ion)) and defect thermodynamic behavior, etc. This presentation is a
condensed review of the technology; and scientifically emphasized description of the value of Mössbauer, NMR and EXAFS, etc.,
microscopic and spectroscopic local structure data in combination with macroscopic XRD lattice parameter/crystal structure data
in both formulating and substantiating the model, and in practical engineering aspect, in view of their well-known application as
solid electrolytes in SOFC (solid oxide fuel cell) technology. I appeal its near quantitative ability to predict and describe their key
characteristic feature of ionic conductivity maximum (σ(ion)(max)) behavior in low dopant (Ln3+) content range.

Biography :

Akio Nakamura is a PhD from University of Tokyo (1975). He is a Senior Researcher at ASRC/ JAEA, studying solid state electrochemistry of fluorite oxides. He
is the author of ~200 peer-reviewed papers, guest editor/organizing committee member of many international conferences. He is the book Editor for books like
“New research trends of fluorite-based oxide materials; from basic chemistry and materials science to engineering applications” from Nova Science Publishers
(NY) published in 2015, and a recipient of Jubilee Gold Medal Award for Excellent Work in Materials Chemistry at the ICFM-2015 convened by Indian Association
of Solid State Chemists and Allied Scientists at Nagpur, India, 2015.