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arXiv · 2011.03086

Avoided ferromagnetic quantum critical point in pressurized La$_5$Co$_2$Ge$_3$

Li Xiang·Elena Gati·Sergey L. Bud'ko·Scott M. Saunders·Paul C. Canfield
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Abstract

We present the pressure-temperature phase diagram La$_5$Co$_2$Ge$_3$ up to $\sim$ 5\,GPa, which was constructed from magnetization, resistivity and specific heat measurements. At ambient pressure, La$_5$Co$_2$Ge$_3$ is an itinerant ferromagnet with a Curie temperature $T_\textrm C\sim$ 4\,K. Upon increasing pressure up to $\sim$ 1.7\,GPa, $T_\textrm C$ is suppressed down to $\sim$ 3\,K. Upon further increasing pressure, our results suggest that La$_5$Co$_2$Ge$_3$ enters a different low-temperature ground state. The corresponding transition temperature, $T^*$, has a nonmonotonic pressure dependence up to $\sim$ 5\,GPa. Our results demonstrate that the ferromagnetic quantum critical point in La$_5$Co$_2$Ge$_3$ is avoided by the appearance of a different, likely magnetically ordered state that has an antiferromagnetic component.

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Li Xiang, Elena Gati, Sergey L. Bud'ko, Scott M. Saunders, Paul C. Canfield. 2020-11-05. Avoided ferromagnetic quantum critical point in pressurized La$_5$Co$_2$Ge$_3$. https://doi.org/10.1103/physrevb.103.054419

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