Structural Chemistry and Magnetic Properties of $R_2Ni_{2-x}In$ (R=Gd-Er, x=0.22 or 0.3) Compounds

X-ray diffraction and magnetic measurements of $R_2Ni_{2 - x}In$ (R = Ho, Dy, x = 0.3 and R = Gd, Tb, Er, x = 0.22) compounds are reported. The compounds crystallize in the tetragonal $Mo_2FeB_2$-type crystal structure (space group P4/mbm). Magnetic measurements reveal antiferromagnetic order with the Néel temperatures $T_{N}$ equal to 26.4 K (Gd), 20.2 K (Tb), 8.3 K (Dy), 7.1 K (Ho), and 6.3 K (Er). For R = Gd, Tb and Er an additional phase transition below $T_{N}$ is observed at 13.5, 13.1, and 5.0 K, respectively.