Magnetism of the alternating monolayer-trilayer phase of La$_3$Ni$_2$O$_7$

Rustem Khasanov; Thomas J. Hicken; Hubertus Luetkens; Zurab Guguchia; Dariusz J. Gawryluk; Vignesh Sundaramurthy; Abhi Suthar; Masahiko Isobe; Bernhard Keimer; Giniyat Khaliullin; Matthias Hepting; Pascal Puphal

paper

Magnetism of the alternating monolayer-trilayer phase of La $_{3}$ Ni $_{2}$ O $_{7}$

arXiv:2512.22371

Abstract

Understanding the magnetic ground state of Ruddlesden-Popper nickelates is crucial, as these materials exhibit superconductivity under high pressure and host competing electronic orders that may play a key role in the pairing mechanism. In this work, we investigate the magnetic properties of the alternating monolayer-trilayer phase of La $_{3}$ Ni $_{2}$ O $_{7}$ (1313-La $_{3}$ Ni $_{2}$ O $_{7}$ ) using muon-spin rotation/relaxation ( $μ$ SR) under both ambient and hydrostatic pressure conditions. The monolayer-trilayer phase develops incommensurate magnetic order below approximately 150 K, with a mean ordering temperature of $T_{S D W} ≃ 123$ K and a transition width of $Δ T_{S D W} ≃ 15$ K. The abrupt onset of the internal magnetic field indicates a first-order-like transition. Hydrostatic pressure ( $p$ ) suppresses the magnetic ordering temperature at a rate of $d T_{S D W} / d p ≃ - 3.9$ K/GPa, demonstrating a progressive destabilization of the ordered state. By comparison with the bilayer 2222-La $_{3}$ Ni $_{2}$ O $_{7}$ and the trilayer 3333-La $_{4}$ Ni $_{3}$ O $_{10}$ systems, and within a unified phenomenological framework, systematic trends are identified linking the pressure dependence of $T_{S D W}$ , the (in)commensurability of the magnetic order, and the character of the magnetic transition. These trends consistently indicate a gradual reduction of electronic correlation strength from the bilayer to the monolayer-trilayer and trilayer nickelates. This hierarchy suggests that the higher superconducting transition temperature observed in the 2222 phase may be closely connected to its more strongly correlated electronic nature. These results position the alternating monolayer-trilayer 1313-La $_{3}$ Ni $_{2}$ O $_{7}$ as an intermediate member linking the magnetic behavior of the bilayer 2222-La $_{3}$ Ni $_{2}$ O $_{7}$ and the trilayer 3333-La $_{4}$ Ni $_{3}$ O $_{10}$ Ruddlesden-Popper compounds.

15 pages, 12 figures

Magnetism of the alternating monolayer-trilayer phase of La3​Ni2​O7​

Abstract

Magnetism of the alternating monolayer-trilayer phase of La $_{3}$ Ni $_{2}$ O $_{7}$