1. Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
2. Ilse Katz Institute for Nano-Scale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
3. Department of Chemical Sciences, Faculty of Exact Science, Ariel University, Ariel 4077625, Israel
4. Cubic Carbon Ceramics, Huntingtown, MD 20639, USA