Effect of In/Sn substitution on magnetism, crystal and electronic structure in Gd(In1-xSnx)3 system

The magnetic, electric transport and electronic structure of a series of polycrystalline Gd(In1-xSnx)(3) intermetallic compounds were investigated by means of experimental and ab initio methods. For all investigated compounds, the multiple magnetic phase transition was detected by means of magnetization and resistivity measurements. Partial replacement of In by Sn atoms is reflected in the oscillating behaviour of the upper Neel temperature (T-N1) and other magnetic parameters but the lower Neel temperature (T-N2) remains almost constant. Electronic structure studied by method indicates that the In/Sn substitution results in an energy shift of the Gd4f and Gd4d lines and a reconstruction of the valence band (VB) near the Fermi level. Especially, the maximum intensity I-max(VB) near the Fermi level varies with Sn content in an oscillatory manner. The observed peculiar features of the electronic structure of the alloys have been reproduced by ab initio density functional calculations. For all compounds, the calculations disclosed the presence of two, close energetically, ground-state antiferromagnetic structures of AFM-I (0 0 1) and AFM-III (1 1 0) type. The ab initio study revealed also that upon the In/Sn substitution, the ground-statemagnetic structure of the compounds changes from AFM-III type for the In-rich side to AFM-I type for a higher Sn content. Our experimental and theoretical investigations demonstrated unambiguously that the observed oscillatory variation of different magnetic parameters of the Gd(In1-xSnx)(3) is driven by the changes in the VB structure of the system upon the In/Sn substitution.