Magnetic structure of the Zr6CoAs2-type Tb6FeBi2 compound

Investigations were made by neutron diffraction experiments on the Zr6CoAs2-type (space group P6b2m no. 189) Tb6FeBi2 compound. Below TC1 = 250(5) K the magnetic structure of Tb6FeBi2 consists of Tb ferromagnetic (0 0 1) layers (μTb = 8.0(3) μB at 70 K). Below TC2 = 60(5) K the Tb6FeBi2 has an incommensurate magnetic structure with a constant propagation vector [0, 0, 0.350(1)]. The propagation vector coincides with the c axis. The magnetic moment of the Tb atoms makes an angle with the c axis (μTb = 8.9(3) μB, μTb = 6.2(4)° at 26 K).