Multi-step magnetic transition in non-centrosymmetric compound CeCoGe 3

Abstract

Single crystal neutron diffraction experiments on non-centrosymmetric pressure-induced superconductor CeCoGe3 were carried out in order to reveal a magnetic structure in the ground state. This compound shows multi-step magnetic transitions at TN1=20 K, TN2=11.5 K and T N3=7.5 K. We have observed the appearance of the magnetic reflection at (1 01/2) together with the weaker one at (10 1/4) and its higher-order harmonics at 2.9K. These results indicate that the ground state magnetic structure consists of two components with dominant q1=(0 01/2) and q2=(0 03/4). No magnetic peak was observed along (0 0 l), indicating that the directions of corresponding antiferromagnetic moments are parallel to the c-axis. Consequently, CeCoGe3 has at least two Ce sites in the ground state with respect to the magnitude of the magnetic moment. © 2009 IOP Publishing Ltd.