Affiliation: | 1.Verkin Institute for Low-Temperature Physics and Engineering,National Academy of Science of Ukraine,Kharkov,Ukraine;2.North Caucasian Mining and Metallurgical Institute,Vladikavkaz, Republic of North Ossetia-Alania,Russia;3.Berbekov Kabardino-Balkarian State University,Nal’chik, Kabardino-Balkarian Republic,Russia |