Microscopic evidence of a new 9R-AgI polytype heterostructure.
The extraordinary high ionic conductivity and the phase transition with large thermal hysteresis of AgI:Al2O3 nanocomposites can be ascribed to the presence of unusual polytype 7H and 9R modification of AgI as mesoscopic heterostructures. In addition to the 7H AgI phase in the composites previously identified by a Rietveld analysis of X-ray diffraction, a new 9R AgI polytype with a characteristic three-fold contrast was directly evidenced by high resolution transmission electron microscopy. The epitaxial intergrowth of various polytypes was also microscopically evidenced which is in accordance with the Rietveld analysis.
Lee
Jong-Sook
JS
School of Materials Science and Engineering and The Research Institute for Catalysis, Chonnam National University, Gwangju 500-757, Korea.
Lee
Ju-Wook
JW
Lee
Jeong Yong
JY
Adams
Stefan
S
Guo
Yu-Guo
YG
Maier
Joachim
J