1. Nanosystem Research Insutitute, AIST (National Institute of Advanced Industrial Science and Technology); Central 4 1-1-1 Higashi Tsukuba Ibaraki 305-8562 Japan
2. Department of Metallurgy and Ceramics Science; Tokyo Institute of Technology; S7-6 2-12-1 Ookayama Meguro-Ku Tokyo 152-8550 Japan
3. Research Department, R & D Division, Taki Chemical Co. Ltd.; 346, Miyanishi, Harima-Cho Kako-Gun Hyogo 675-0145 Japan