1. Department of Physics, Nagoya University, Nagoya 464-8602, Japan
2. Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
3. Research Unit for Development of Organic Superconductors, Ehime University, Matsuyama 790-8577, Japan
4. Geodynamics Research Center (GRC), Ehime University, Matsuyama 790-8577, Japan