(Magneto)Transport Properties of (TiZrNbNi)(1−x)Cu(x) and (TiZrNbCu)(1−x)Co(x) Complex Amorphous Alloys

We present a systematic study of electrical resistivity, superconductive transitions and the Hall effect for three systems of compositionally complex amorphous alloys of early (TE) and late (TL) transition metals: [Formula: see text] and [Formula: see text] in a broad composition range of [Formula: see text] as well as [Formula: see text] , [Formula: see text] and [Formula: see text]. All samples showed high resistivity at room temperature, 140–240 [Formula: see text] Ω cm, and the superconducting transition temperatures decreased with increasing late transition metal content, similar to binary amorphous and crystalline high-entropy TE-TL alloys. The Hall coefficient [Formula: see text] was temperature-independent and positive for all samples (except for (TiZrNbCu) [Formula: see text] Co [Formula: see text]), in good agreement with binary TE-TL alloys. Finally, for the temperature dependence of resistivity, as far as the authors are aware, we present a new model with two conduction channels, one of them being variable range hopping, such as the parallel conduction mode in the temperature range 20–200 K, with the exponent [Formula: see text]. We examine this in the context of variable range hopping in granular metals.