paper

Competing Charge/Spin-Stripe and Correlated Metal Phases in Trilayer Nickelates (Pr $_{1 - x}$ La $_{x}$ ) $_{4}$ Ni $_{3}$ O $_{8}$

arXiv:2202.03479

Abstract

Low-valent nickelates R $_{n + 1}$ Ni $_{n}$ O $_{2 n + 2}$ (R = rare earth) containing Ni $^{1 +}$ (d $^{9}$ ) with a quasi-two-dimensional (quasi-2D) square planar coordination geometry possess structural and electronic properties that are similar to those of high-Tc cuprates, including superconductivity itself in the doped infinite layer ( $n = \infty$ ) RNiO $_{2}$ system. Within this R $_{n + 1}$ Ni $_{n}$ O $_{2 n + 2}$ nickelate family, the crystallographic isomorphs Pr $_{4}$ Ni $_{3}$ O $_{8}$ and La $_{4}$ Ni $_{3}$ O $_{8}$ exhibit singularly different ground states: Pr $_{4}$ Ni $_{3}$ O $_{8}$ is metallic and La $_{4}$ Ni $_{3}$ O $_{8}$ is a charge- and spin-stripe ordered insulator. To explore and understand the ground state evolution from metallic Pr $_{4}$ Ni $_{3}$ O $_{8}$ to stripe-ordered La $_{4}$ Ni $_{3}$ O $_{8}$ in the R $_{4}$ Ni $_{3}$ O $_{8}$ family, we have grown a series of isovalent-substituted single crystals (Pr $_{1 - x}$ La $_{x}$ ) $_{4}$ Ni $_{3}$ O $_{8}$ . Combining thermodynamic, transport, magnetic, and synchrotron X-ray single crystal diffraction measurements, we reveal a transition between metallic and stripe-insulator phase regions, with a putative quantum phase transition at x = 0.4. We propose two possible models for (Pr $_{1 - x}$ La $_{x}$ ) $_{4}$ Ni $_{3}$ O $_{8}$ : an electronically inhomogeneous system that could serve as a candidate for exploring quantum Griffiths phase physics and a homogeneous system with a putative quantum critical point at the phase boundary.

Competing Charge/Spin-Stripe and Correlated Metal Phases in Trilayer Nickelates (Pr1−x​Lax​)4​Ni3​O8​

Abstract

Competing Charge/Spin-Stripe and Correlated Metal Phases in Trilayer Nickelates (Pr $_{1 - x}$ La $_{x}$ ) $_{4}$ Ni $_{3}$ O $_{8}$