Neutron diffraction studies on structural and magnetic properties of RE2NiGe3 (RE=La, Ce)

Abstract

We report the crystallographic properties of RE(2)NiG(e)3 (RE=La, Ce) synthesized by arc melting. Rietveld refinement on the powder neutron diffraction (ND) data suggest both compounds are isostructural and crystallize in the non-centrosymmetric Er2RhSi3 type structure having hexagonal space group P2c. In the crystal structure of RE2NiGe3, two dimensional arrangements of nickel and germanium atoms lead to the formation of hexagonal layers with rare earth atoms sandwiched between them. Magnetic susceptibility measurements performed in low fields exhibit antiferromagnetic ordering in cerium compound around (To=) 3.2 K. Neutron diffraction measurements at 2.8 K (i.e., at T< To) neither show any change in the intensities of the diffraction lines nor indicate the appearance of any new diffraction lines in the Q-range of 0.47-7.34 A(-1), thus ruling out any long-range magnetic order. (C) 2014 Elsevier Inc. All rights reserved.