1. Faculty of Science and Engineering, Ishinomaki Senshu University, Ishinomaki, Miyagi 986-8580, Japan
2. Faculty of Humanities, Morioka University, Takizawa, Iwate 020-0694, Japan
3. Institute for Materials Research, Tohoku University, Sendai 980-8857, Japan
4. The Research Institute for Electric and Magnetic Materials, Tomiya, Miyagi 981-3341, Japan