1. School of Advanced Materials Engineering and Research Center of Advanced Materials Development, Chonbuk National University, Jeonju 561-756, South Korea
2. National University of Science and Technology MISiS, Leninskiy pr. 4, Moscow 119049, Russia
3. Institute of Rare Metals, B. Tolmachevsky, 5, Moscow 119017, Russia
4. Institute of Microelectronics Technology and High Purity Materials, Russian Academy of Science, 6, Academician Ossipyan str., Chernogolovka, Moscow Region 142432, Russia
5. Technological Institute for Superhard and Novel Carbon Materials, 7 Centralnaya St., Troitsk, Moscow 142190, Russia
6. University of Florida, Gainesville, Florida 32611, USA