1. Department of Physics and Astronomy; Texas Christian University; Box 298840 Fort Worth TX 76129 USA
2. Kyiv National Taras Shevchenko University; 64 Volodymyrska Str. 01601 Kyiv Ukraine
3. Paine College; 1235 Fifteenth Street Augusta GA 30901 USA
4. O. Chuiko Institute of Surface Chemistry of NASU; 17 Gen. Naumov Str. 03164 Kyiv Ukraine
5. V. Bakul Institute for Super Hard Materials; 2 Avtozavodska Str. 04074 Kyiv Ukraine