Magnetic phase diagram and magnetic structure of Gd(Sn1-xInx)3

We have carried out measurements of the magnetic susceptibility, Moessbauer spectra, and specific heat on Gd(Sn1-xInx)3. We observe an oscillatory variation of the antiferromagnetic transition temperature TN1 across the series from GdSn3 (x=0.0) to GdIn3 (x=1.0). For the range of In concentrations 0.265≤x≤0.565, we find a second magnetic transition, at a temperature TN2 well below TN1. These measurements along with the temperature dependence of 119Sn Moessbauer spectra indicate that the ground-state magnetic structure is a type-I antiferromagnetic ordering for the Sn-rich side (0≤x≤0.25) and is a type-II for the very rich In side (x→1.0). For the range of In concentrations 0.265≤x≤0.565 the magnetic structure is also of type I in the temperature interval TN2<T<TN1. The magnetic structure for 0.265≤x≤0.565 with T<TN2 and also for 0.565<x<1.0 with T<TN1 could be a canted antiferromagnetic ordering state. copyright 1996 The American Physical Society