REPt3Si (RE = La, Pr, Nd, Sm and Gd):: isotypes of the heavy fermion superconductor CePt3Si

Novel representatives REPt3Si (RE = La, Pr, Nd, Sm and Gd) of the CePt3B type have been synthesized and characterized by means of Rietveld x-ray powder diffraction. Measurements of the magnetic susceptibility, isothermal magnetization, temperature dependent specific heat as well as temperature and field dependent resistivity were employed to derive basic information on the low temperature behaviour. Long range antiferromagnetic order from 2.2 K (CePt3Si) to 15.1 K (GdPt3Si) was observed. PrPt3Si, however, is nonmagnetic, at least down to 400 mK, as a consequence of crystalline electric field splitting of the non-Kramers ion Pr3+ in tetragonal symmetry. Whilst the ordering temperature of SMPt3Si appears to be almost unaffected in external fields up to 12 T, magnetic order in GdPt3Si, although twice as high as for the Sm homologue, is easily suppressed by external magnetic fields due to the absence of anisotropy.