1. Research Center for Advanced Carbon Materials, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan, Department of Materials Science and Engineering, Meijo University, 1-501 Tenpaku-ku, Nagoya 468-8502, Japan, and Noritake Company Ltd., 728-23 Tsumura-cho, Ise, Mie 516-1103, Japan