Anisotropic magnetization, resistivity and heat capacity of single crystalline R3Ni2−xSn7 (R=La, Ce, Pr and Nd)

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.