  We present a detailed study of R3Ni2-xSn7 (R = La, Ce, Pr and Nd) single
crystals by measurements of crystal structure, stoichiometry, temperature
dependent magnetic susceptibility, magnetization, electrical resistivity,
magnetoresistance, and specific heat. This series forms with partial Ni
occupancy with x varying from ~ 0.1 for R = La to ~0.7 for R = Nd. The
electrical resistivity of this series follows metallic behavior at high
temperatures. Determination of clear anisotropies as well as antiferromagnetic
ordering temperatures for R3Ni2-xSn7 (R = Ce, Pr and Nd) have been made. For
Pr3Ni1.56Sn7 and Nd3Ni1.34Sn7, multiple magnetic transitions take place upon
cooling. Metamagnetic transitions in this family (R = Ce, Pr and Nd) were
detected for applied magnetic fields below 70 kOe. An H-T phase diagram of
Ce3Ni1.69Sn7 was assembled to shed light on its low field properties and to
rule out possible quantum critical effects.
