1. Department of Organic and Polymeric Materials, Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8552, Japan
2. National High Magnetic Field Laboratory and Department of Physics, Florida State University, Tallahassee, FL 32310, U.S.A.
3. Department of Applied Chemistry, Ehime University, Matsuyama 790-8577, Japan
4. Department of Materials Science and Technology, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan