1. College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, 29 Jiangjun Avenue, Jiangning
District, Nanjing, Jiangsu 211106, P. R. China
2. Department of Mechanical Engineering, University of Texas at Dallas, 800 W. Campbell Rd., Richardson, Texas 75080, United States
3. School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
4. Department of Physics, University of Texas at Dallas, 800 W. Campbell Rd., Richardson, Texas 75080, United States