[1] Department of Electrical and Computer Engineering, University of Thessaly, Volos,38333, Greece
[2] B. Verkin Institute for Low Temperature Physics and Engineering, The National Academy of Sciences of Ukraine, Kharkiv,61103, Ukraine
[3] Institute for Low Temperatures and Structure Research, Polish Academy of Sciences, Wroclaw,50-422, Poland
[4] V. N. Karazin Kharkiv National University, Kharkiv,61022, Ukraine
[5] Department of Materials, Imperial College London, London,SW7 2BP, United Kingdom