Magnetic interactions in Pr 1− xTb xMn 2Ge 2

Abstract

The magnetic moments in the rare earth and Mn sublattices of RMn 2Ge 2, where R is a rare earth element, feature a variety of ordering configurations. In PrMn 2Ge 2 and TbMn 2Ge 2, the interlayer magnetic coupling in the Mn sublattice is, respectively, ferromagnetic and antiferromagnetic below about 350 K. At low temperatures, the rare earth sublattice also orders and reconfigures the ordering in the Mn sublattice. In this study, we investigate the variations in the magnetic properties of Pr 1− x Tb x Mn 2Ge 2 as a function of rare earth concentration by examining the evolution of the features in the temperature dependence of the magnetization. The results of earlier neutron diffraction and Mössbauer studies on samples with x=0 and 1 are also used for interpreting the magnetization data and to give an account of the competing effects between various magnetic structures in the Mn and rare earth sublattices. The results are summarized in the Pr 1− x Tb x Mn 2Ge 2 magnetic phase diagram.