Low pressure phase diagram of CeCoGe3

Abstract

We have performed measurements of the Hall magnetization and electrical resistivity on a pressure-induced antiferromagnetic heavy fermion superconductor CeCoGe3 at pressures up to ~1.7 GPa, which crystallizes in the tetragonal BaNiSn3-type structure without inversion symmetry. We have clarified that five successive phase transitions appear at ambient pressure. As pressure is applied, these transitions approach one another until ~1.2 GPa, and then separate again. We have also found another phase transition emerges above ~0.5 GPa, which is consistent with a recent Co-NQR study. From these results, we propose a low pressure P-T phase diagram, which contains at least eight ordered phases below ~2 GPa. This phase diagram is consistent with a recent reported high pressure phase diagram.