The effect of hydrostatic pressure on magnetic properties of partially crystallized Co-based amorphous alloy

Melt-spun Co66Nb9Cu1Si12B12 metallic glass ribbon (T-C approximate to 150 K ) was used to produce nanocrystalline samples by annealing at 590 degreesC and 610 degreesC for 1 h. Their magnetic properties were measured in a supe rconducting quantum interference device (SQUID) magnetometer as a function of temperature (10-250 K) in fields to 3 kOe at zero and similar to7 kbar h ydrostatic pressure. The pressure shifts the Curie point of the amorphous m atrix to lower temperature by -0.55 K/kbar. The difference between the zero -field-cooled (ZFC) and field-cooled (FC) dependences of the magnetization indicates mictomagnetic properties at low temperatures (T < T-C); for highe r temperatures, the samples essentially are an assembly of superparamagneti c particles. The analysis of the Henkel plots for both samples points to th e presence of interactions, whose sensitivity to pressure depends on the vo lume fraction of the crystallites. (C) 2001 Elsevier Science B.V. All right s reserved.