1. Ceramic Research Institute, National Institute of Advanced Industrial Science and Technology, 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-8560, Japan, Department of Earth and Planetary Sciences, Faculty of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan, Department of Materials Science and Technology, Faculty of Science and Technology, Hirosaki University, 3, Bunkyo-cho, Hirosaki 036-8561, Japan, and Department of Materials Science and Engineering, Faculty of...