Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7970902 | Materials Characterization | 2014 | 6 Pages |
Abstract
Two types of Li7La3Zr2O12 (LLZ) pellets were prepared containing Al and Si impurities, and their grain boundaries characterized using scanning electron microscopy (SEM) with energy-dispersed X-ray (EDX) elemental mapping, transmission electron microscopy (TEM), selected-area electron diffraction (SAED), electron energy-loss spectroscopy (EELS), and high-resolution transmission electron microscopy (HRTEM). In the LLZ pellets containing a small amount of both Al and Si, the total conductivity and density were found to be greater than that of LLZ containing Al alone. Using EDX and TEM, the Al and Si were confirmed to accumulate predominantly at grain-boundary regions. EELS and SAED were used to determine the presence of crystallites of LiAl5O8 and LiAlSiO4 in the Al-only and Si and Al containing specimens, respectively. HRTEM observations clarified that in the case of LiAlSiO4, nano-sized particles exist within an amorphous phase matrix, with a microstructure similar to that in a glass-ceramic. The presence of grain-boundary phases is shown to greatly affect the grain boundary resistance, in the case of the LiAlSiO4 glass-ceramic-type phase resulting in a noticeable improvement of the total conductivity.
Keywords
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Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Ki Hyun Kim, Tsukasa Hirayama, Craig A.J. Fisher, Kazuo Yamamoto, Takeshi Sato, Kinuka Tanabe, Shota Kumazaki, Yasutoshi Iriyama, Zempachi Ogumi,