The temperature-pressure phase diagram of La₅(Co_1-xNi_x)₂Ge₃; x = 0.03

La₅Co₂Ge₃ is an itinerant ferromagnet (FM) system that undergoes a second order phase transition at 3.8 K with a low-field saturated moment of about 0.1 μ_B/Co¹, suggesting that the magnetic order is could be fragile. Under applied hydrostatic pressure, the FM quantum critical point in undoped La₅Co₂Ge₃ is avoided by the emergence of a different, likely antiferromagnetically ordered, state²­. Our recent studies on La₅(Co_1-xNi_x)₂Ge₃ with x = 0.01 - 0.10 show that the system can be tuned from FM ground state to a different, antiferromagnetic, ground state with a clear and well-defined signature in magnetization as well as resistivity. We now investigate the high pressure electrical properties of La₅(Co_1-xNi_x)₂Ge₃ with x = 0.03, where the sample has just crossed into the clean AFM ground state, to study the evolution of the AFM ordering in this system. The temperature-pressure magnetic phase diagram of La₅(Co_1-xNi_x)₂Ge₃; x = 0.03 is constructed. Details of this diagram will be discussed and compared to the T-P work in the undoped system.

 

1. Saunders, S. M. et al., Phys Rev B 101, (2020).

2. Xiang, L. et al., Phys Rev B 103, (2021).