New members of ThMn12-structure family RFe(11.35)Nb(0.65) (R=Y, Dy, Er
) have been synthesized and studied by x-ray diffraction, ac susceptib
ility measurements and thermomagnetic analysis. Spin reorientation tra
nsitions were observed in DyFe11.35Nb0.65 and ErFe11.35Nb0.65 compound
s. The transition temperatures of spin reorientation were determined t
o be T-sr1=160 K and T-sr2=235 K for DyFe11.35Nb0.65, and T-sr=41 K fo
r ErFe11.35Nb0.65, respectively. The spin reorientation transitions ar
e quenched by nitrogenation.