By using a single-ion crystalline electric field (CEF) model, the spin
-reorientation phenomena of NdFe9.8V2.2, TbFe12-xVx (x = 1.5, 2.0, 2.7
5 and 4) and ErFe12-xVx (x = 1.5, 2.0 and 2.75) compounds have been an
alysed. The CEF parameters B-n(m) are obtained by fitting experimental
data. The role of the value B-2(0) and the effect of the 3d-4f intera
ction in analysing the spin-reorientation of R(Fe,V)(12) compounds are
discussed.