1. Department of Physics, Cross River University of Technology 1 , Calabar, Nigeria
2. Department of Physics, National Technical University “Kharkiv Polytechnic Institute” 2 , Kharkiv 61002, Ukraine
3. B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 3 Kharkiv 61103, Ukraine
4. , 3 Kharkiv 61103, Ukraine