Magnetostriction of Dy-rich Tb/sub x/Dy/sub 1-x/ single crystals

Magnetostriction and differential scanning calorimetry measurements were conducted on the Tb/sub x/Dy/sub 1-x/ alloy system for 0.33>or=x>or=0. The magnetostriction measurements extend from 80 K to 300 K and cover the ferromagnetic, antiferromagnetic spiral, and paramagnetic temperature regions with fields of 6-20 kOe. From the data the authors derive the two lowest order magnetostriction constants, lambda /sup gamma .2/ and lambda /sup gamma .4/, as well as the basal plane anisotropy, K/sub 6//sup 6/. At 80 K, lambda /sup gamma .2/>7*10/sup -3/ for all alloys. While lambda /sup gamma .2/ is almost independent of alloy concentration (except at high temperatures), lambda /sup gamma .4/ decreases substantially with increasing Dy concentration, approaching zero for 0.17>x>0. As reported previously, the basal plane anisotropy was found to compensate at temperatures below 100 K in the x=0.67 and 0.50 alloys. This compensation is found to occur at higher temperatures in the x=0.33 and 0.17 alloys. The temperatures at which this occurs are presented in a magnetic phase diagram along with the calorimetrically determined Curie and Neel temperatures.>