Magnetic order and crystal structure study of YNi4Si-type NdNi4Si

Abstract

Magnetic measurements and neutron powder diffraction investigation of the magnetic structure of the orthorhombic YNi4Si-type (space group Cmmm) NdNi4Si compound are presented. The magnetocaloric effect of NdNi4Si is calculated in terms of the isothermal magnetic entropy change and it reaches the maximum value of –3.3 J/kg K for a field change of 50 kOe near TC=12 K. Below ~12 K, NdNi4Si exhibits a commensurate b-axis collinear ferromagnetic ordering with the Cmm′m magnetic space group in a zero magnetic field. At 1.5 K, the neodymium atoms have the magnetic moment of 2.37(5) μB. The orthorhombic crystal structure and its thermal evolution are discussed in comparison with the CaCu5-type compound.