On the crystal structure and magnetism of CePtSn at low temperatures

Results of powder X-ray diffraction measurements done on the orthorhombic CePtSn in the temperature range 4-300 K are reported. Rietveld refinement of diffraction data collected at each temperature revealed anomalies in the temperature dependence of lattice parameters that can be associated with magnetic phase transitions in this intermetallic compound at 5 (T-M) and 7.5 K (T-N). The dominant change of the lattice parameters was observed at the magnetic transition, at T-N, from the paramagnetic to the antiferromagnetic phase. A shallow minimum of the lattice parameters a and b above T-N is tentatively attributed to antiferromagnetic correlations in the paramagnetic range. (C) 2002 Elsevier Science BY All rights reserved.