1. Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
2. Research Institute for Advanced Materials and Devices, Kyocera Corporation, 3-5-3 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237, Japan