Magnetic phase diagram of EuPdSn2

A magnetic phase diagram for EuPdSn2 is constructed based on magnetization, dc susceptibility and specific heat as a function of applied field (B), and neutron diffraction results at B=0. The contribution of the ferromagnetic (FM) and antiferromagnetic components to the measured magnetic susceptibility can be separated and weighted as a function of B by taking the temperature dependence of the neutron diffraction counts from the FM phase at B=0 as reference. In the magnetically ordered phase, the temperature dependence of the specific heat does not follow the mean field prediction for the Eu2+J=7/2 quantum number but rather that for J=5/2. This deviation and the consequent discrepancy for the entropy evolution is discussed in the context of a non-Zeeman distribution of the eightfold ground state. Comparing the respective variations of the magnetization M(T,B) and the entropy S(T,B), the thermodynamic relationship ∂M/∂T=∂S/∂B=0 is observed for the ranges 0<10 K and 0<0.4 T.