1. Institute of Physics and Technology Ural Federal University Ekaterinburg 620002 Russian Federation
2. Institute of Material Science and Metallurgy Ural Federal University Ekaterinburg 620002 Russian Federation
3. Racah Institute of Physics The Hebrew University Jerusalem 91904 Israel
4. Department of Physics University of Helsinki Gustaf Hällströmin katu 2a, PO Box 64 FI‐00014 Helsinki Finland
5. Finnish Geospatial Research Institute Geodeetinrinne 2 02430 Masala Finland