Magnetic properties of amorphous CoxNb100 x alloys produced by mechanical alloying

Three amorphous CoxNb100 x alloys, Co25Nb75, Co57Nb43 and Co80Nb20, 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 aCo57Nb43 the hardest magnetic material among the three alloys. Further addition of Co produces a soft alloy.