Double phase transition and magnetic ordering in NdFe2Si2 single crystal

Abstract We have investigated a single crystal of NdFe2Si2 by variety of macro- and microscopic experiments in wide range of temperatures and magnetic fields. The results confirmed antiferromagnetic ordering below the Neel temperature TN≈14 K and uniaxial magnetocrystalline anisotropy with easy magnetization direction along the c-axis. Specific heat and dilatometry data exhibit an additional sharp anomaly below the TN, in particular at Tt=13.1 K, which was tentatively considered as a signature of an order–order magnetic phase transition. The neutron diffraction experiment, however, reveals no evidence of an order–order magnetic phase transition and confirms existence of only one magnetic structure up to the TN with propagation vector q = ( 0 0 1 2 ) . The temperature dependence of the electrical resistivity shows only a single anomaly (at TN), consistently with neutron diffraction results. Furthermore, comprehensive neutron diffraction experiment is scheduled.