Exploring the complex magnetic phase diagram of Ce2PdGe3: A neutron powder diffraction and μsR study

The magnetic state of the tetragonal compound Ce2PdGe3, which crystallizes in the space group P42/mmc, a derivative of the α-ThSi2 structure, has been investigated by magnetic susceptibility, heat capacity, muon spin relaxation (μSR), and neutron diffraction measurements. Heat capacity data indicate two separate magnetic phase transitions at TN1=10.7 K and TN2=2.3 K. The presence of bulk long-range magnetic order is confirmed by our μSR study below 11 K, where a drop of nearly 2/3 in the muon initial asymmetry and a sharp increase in the muon depolarization rate were observed. Neutron powder diffraction reveals that only one out of two Ce sites becomes magnetically ordered with magnetic propagation vector κ=(0) at TN1, adopting an antiferromagnetic arrangement of magnetic moments μCe3+=1.78(1)μB along the c axis. At TN2 the second Ce site orders similarly, following the same magnetic propagation vector κ=(0), showing, however, at the same time a significant ferromagnetic component within the tetragonal basal plane.