Formation of short-range magnetic order and avoided ferromagnetic quantum criticality in pressurized LaCrGe₃

LaCrGe₃ has emerged as a model system for the study of the avoidance of ferromagnetic (FM) quantum criticality in itinerant magnets [1,2]. In this talk, we will present our results from combining thermodynamic, transport, x-ray and neutron scattering as well as μSR measurements on LaCrGe₃ under pressure to identify the various phases in the phase diagram across the avoided FM quantum-critical point. We present thermodynamic evidence (i) for the first-order character of the FM transition at lowest temperatures and (ii) for the formation of new phases at high pressures. From our microscopic data, we infer that short-range FM ordered clusters rather than long-range modulated antiferromagnetism exist in these high-pressure phases. Overall, our results suggest that the phase diagram of LaCrGe₃ combines features that are usually associated with avoided criticality in either clean or strongly disordered FM metals.
[1] Taufour et al., PRL 117, 037207 (2016); [2] Kaluarachchi et al., Nat. Commun. 8, 546 (2017).