Annealing and magnetic field effects on the resistivity of Fe-rich Fe-Zr glasses

Electrical resistivity at zero and applied magnetic fields has been measured in as-quenched and annealed Fe91Zr9 and Fe90Zr10 amorphous alloys between 4 and 320 K. Fe91Zr9 remained amorphous after annealing at 400 K (1 h) while in Fe90Zr10, traces of crystallites were observed. Similar annealings at 600 K were sufficient to crystallize both alloys, with alpha-Fe as the main product. A.c. susceptibility shows small changes in the Curie and spin-glass temperatures upon annealing. The resistivity displays a minimum at high temperatures (congruent to 250 K), slightly influenced by a magnetic field and thermal treatment. The resistivity is a competition of contributions in which the structure plays the most important role. The presence of magnetic inhomogeneities could also favor an enhanced electronic localization. (C) 1997 Elsevier Science Ltd.