Magnetic behavior of the ternary silicide U3Cu4Si4

The orthorhombic ternary silicide U3Cu4Si4 has been studied by means of electrical resistivity, AC- and DC-magnetization measurements and neutron powder diffraction. Magnetic measurements reveal that U3Cu4Si4 orders antiferromagnetically below TN=136(2) K but its magnetization shows also an anomaly in the temperature range 40–50 K. This last behavior is influenced by the cooling process of the sample. However, neutron diffraction investigation exhibits that U3Cu4Si4 is a collinear antiferromagnet down to 1.5 K with U-magnetic moments (1.20(4) μB) parallel to the c-axis. This magnetic structure is discussed in relation to those reported for U3Cu4Ge4 and UCu2Si2 which present some structural similarities.