Avoided ferromagnetic quantum critical point in pressurized La5Co2Ge3

We present the pressure-temperature phase diagram La5Co2Ge3 up to ~ 5 GPa, which was constructed from magnetization, resistivity, and specific heat measurements. At ambient pressure, La5Co2Ge3 is an itinerant ferromagnet with a Curie temperature TC ~ 4 K. Upon increasing pressure up to ~ 1.7 GPa, TC is suppressed down to ~ 3 K. Upon further increasing pressure, our results suggest that La5Co2Ge3 enters a different low-temperature ground state. The corresponding transition temperature T* has a nonmonotonic pressure dependence up to ~ 5 GPa. Our results demonstrate that the ferromagnetic quantum critical point in La5Co2Ge3 is avoided by the appearance of a different, likely magnetically ordered, state that has an antiferromagnetic component.