Resistivity and magnetoresistance studies of superconducting Al5 Nb₃Au and Ti₃Sb compounds

Abstract

The normal-state resistivity rho (T) and longitudinal magnetoresistance of superconducting A15 Nb₃Au and Ti₃Sb compounds have been measured. The resistivities of these compounds have been measured from just above their superconducting transition temperature (T_c) to room temperature. The magnetoresistance has been measured up to a field of 4.5 T. At high temperatures (T>200K) their resistivities show a non-linear behaviour with temperature which is a characteristic feature of many A15 compounds. However, at low temperatures (T<40K), the rho (T) of these compounds show a T² dependence which was so far seen only in high-T_c A15 compounds. The data are fitted to several theories which try to explain the low- and high-temperature resistivities of A15 alloys. The magnetoresistance data show a linear dependence on field which is not very well understood.