Magnetic properties of amorphous Co$_x$Nb$_{100-x}$ alloys produced by mechanical alloying

TL;DR

This study investigates the magnetic properties of amorphous Co-Nb alloys produced by mechanical alloying, revealing how Co content influences magnetic hardness and identifying Co$_{57}$Nb$_{43}$ as the hardest among tested compositions.

Contribution

The paper presents the production and magnetic characterization of amorphous Co-Nb alloys with different compositions, highlighting the optimal Co content for maximum magnetic hardness.

Findings

Co$_{57}$Nb$_{43}$ is the hardest magnetic alloy among those tested.

Higher Co content beyond 57% results in softer magnetic properties.

Saturation field decreases with increasing Co content.

Abstract

Three amorphous Co$_x$Nb$_{100-x}$ alloys, Co$_{25}$Nb$_{75}$, Co$_{57}$Nb$_{43}$ and Co$_{80}$Nb$_{20}$, were produced by Mechanical Alloying starting from the elemental powders. Their magnetic properties were determined using an alternating gradient force magnetometer (AGFM), and the remanent magnetizations, saturation fields and coercive fields were obtained from the hysteresis loop. The alloys have a relatively high saturation field, which decreases as the composition becomes richer in Co. The coercivity and remanent magnetization reach an optimal value around 57% at.Co, making {\em a}-Co$_{57}$Nb$_{43}$ the hardest magnetic material among the three alloys. Further addition of Co produces a soft alloy.