Spin reorientation phenomena in the Dy1-xYxFe11Ti (x = 0, 0.2, 0.4, 0.
6, 0.8 and 1) compounds have been studied by ac susceptibility and mag
netization measurements on bulk and magnetically aligned powder sample
s. The observed concentration dependence of the spin reorientation tem
peratures and the temperature dependence of the cone Structure of this
series of compounds have been analyzed on the basis of the crystal fi
eld model. A set of crystal field parameters is proposed.