Interrelation between Crystal and Magnetic Structures in La1 – xTbxMn2Si2 Compounds

The crystal and magnetic structures of La1 – xTbxMn2Si2 (0 ≤ x ≤ 1) compounds have been studied using X-ray diffraction and magnetic neutron diffraction (ND) methods. It is shown that at 4.2 K, as the Tb concentration increases, a decrease in the lattice parameters and an increase in the Tb–Mn exchange interactions lead to a change in the type of Mn–Mn interlayer magnetic ordering from ferromagnetic to antiferromagnetic at x ≤ 0.2 and again to ferromagnetic ordering at x ≥ 0.6. The long-range magnetic order in the Tb sublattice is not found in compounds with x ≤ 0.4. The magnetization curves in strong pulsed magnetic fields demonstrate the presence of magnetic phase transitions induced by magnetic field and the coexistence in samples of magnetic phases with ferromagnetic and antiferromagnetic ordering of manganese in samples.