Superconductivity, negative magnetoresistance, and anisotropy of the conductivity of YFe{sub}4Al{sub}8 and ScFe{sub}4Al{sub}8 single crystals in the frequency range 0-10{sup}8 Hz

摘要

The anisotropy of the electrical resistivity of YFe{sub}4Al{sub}8 and ScFe{sub}4Al{sub}8 single crystals is investigated for the first time in the frequency range 0-10{sup}8 Hz and temperature range 300-4.2 K. It is found that the conductivity is higher along the growth axis of the crystals than in the perpendicular direction, while the parameters governing the antiferromagnetic ordering, negative magnetoresistance, and superconductivity effects observed in these single crystals are isotropic. Some effects known previously for poly crystalline high-T{sub}c superconductors containing magnetic impurities are observed in the single crystals investigated and are found to be anisotropic in them.