Strongly Coupled Electronic, Magnetic, and Lattice Degrees of Freedom in LaCo5 under Pressure

TL;DR

This study investigates how pressure influences the electronic, magnetic, and lattice properties of LaCo5, revealing a coupled topological transition and lattice collapse that affect its magnetic behavior.

Contribution

It provides the first high-pressure measurements confirming a predicted electronic topological transition and its impact on the magneto-elastic properties of LaCo5.

Findings

Anisotropic lattice collapse of the c-axis near 10 GPa

Change in majority charge carriers under pressure

Evolution of the anomalous Hall effect linked to magnetization

Abstract

We have performed the first high-pressure magnetotransport and x-ray diffraction measurements on ferromagnetic LaCo5, confirming the theoretically predicted electronic topological transition driving the magneto-elastic collapse seen in the related compound YCo5. Our x-ray diffraction results show an anisotropic lattice collapse of the c-axis near 10 GPa that is also commensurate with a change in the majority charge carriers evident from high-pressure Hall effect measurements. The coupling of the electronic, magnetic and lattice degrees of freedom is further substantiated by the evolution of the anomalous Hall effect, which couples to the magnetization of the ordered state of LaCo5.