Magnetovolume effects in Zr-(Fe1-xCox)2

Abstract

The thermal expansion and Zr(Fe_1-xCo_x)₂ have been measured. The results indicate that the magnetovolume coupling between spontaneous volume magnetostriction and spontaneous magnetisation is very large and is almost independent of the concentration of Co in the ferromagnetic region (i.e. for x=0.0-0.4). Furthermore, an extraordinarily large negative thermal expansion at low temperatures and a large forced volume magnetostriction at 4.2K have been observed in the ferromagnetic compound with x=0.4, both of which are comparable in magnitude to those observed in Fe-Ni Invar alloys. Fairly large forced volume magnetostriction, which does not vary linearly with the applied fields, has been observed in mictomagnetic compounds with x=0.5 and 0.6.