Research projects

We have studied Cr-doping effects on the suppressed magnetism and the electronic structure of quasi-2D layered oxypnictide CeFePO with alternating stack of Ce2O2 and Fe2P2 layers to find two quantum critical points (Cr5%, Cr45%) and reveal novel Kondo lattice picture as follows. The increasing phenomena of the electronic specific heat of CeFePO indicates that the existence of the Kondo singlet was confirmed below 12 K (Kondo temperature). On the other hand, in Cr20%, the appearance of the ferromagnetic transition, the decrease with remarkable electronic thermal capacity and the Kondo breakdown phenomenon are observed below 6 K. Also, the increase of the magnetic phase transition temperature due to applied magnetic field is confirmed, indicating the existence of the ferromagnetic fluctuation in Cr20%. Moreover, from the 57Fe Mossbauer spectrum analysis of Cr50%, it is expected that Fe spin states change into a spin density wave (SDW) below 25 K.