Magnetic Ordering in Kondo Lattice Compound YbIr3Si7

We discovered a new ytterbium intermetallic compound YbIr3Si7 (space group: R3c, #167). The single crystal was obtained via the flux method. We measure the electric resistivity, specific heat, and magnetization of this material. YbIr3Si7 is a Kondo lattice compound having a high magnetic order temperature of 18 K, and it exhibits double magnetic transitions at 4 and 18 K. We evaluate the magnetic order temperature of 18 K using the Arrott plot measured in the magnetic field along the c-axis. The spontaneous moment of this material is 0.35 μB, and this value is much smaller than that of a free Yb3+ ion of 4.54 μB. Canted-antiferromagnetic stacking along the c-axis may be realized below 18 K, where magnetic moments ferromagnetically align on a Yb triangular lattice in the c-plane.