Crystal structure, properties and pressure-induced insulator-metal transition in layered kagome chalcogenides

Abstract

Layered materials with kagome lattice have attracted a lot of attention due to the presence of nontrivial topological bands and correlated electronic states with tunability. In this work, we investigate a unique van der Waals (vdW) material system, $A_2{M}_3{X}_4$ ($A$ = K, Rb, Cs; $M$ = Ni, Pd; $X$ = S, Se), where transition metal kagome lattices, chalcogen honeycomb lattices and alkali metal triangular lattices coexist simultaneously. A notable feature of this material is that each Ni/Pd atom is positioned in the center of four chalcogen atoms, forming a local square-planar environment. This crystal field environment results in a low spin state $S$ = 0 of Ni${}^{2+}$/Pd${}^{2+}$. A systematic study of the crystal growth, crystal structure, magnetic and transport properties of two representative compounds, Rb${}_2$Ni${}_3$S${}_4$ and Cs${}_2$Ni${}_3$Se${}_4$, has been carried out on powder and single crystal samples. Both compounds exhibit nonmagnetic $p$-type semiconducting behavior, closely related to the particular chemical environment of Ni${}^{2+}$ ions and the alkali metal intercalated vdW structure. Additionally, Cs${}_2$Ni${}_3$Se${}_4$ undergoes an insulator-metal transition (IMT) in transport measurements under pressure up to 87.10 GPa without any structural phase transition, while Rb${}_2$Ni${}_3$S${}_4$ persists in its semiconducting behavior.

9 pages, 6 figures

References in corpus (33)

• Giant anomalous Hall effect in a ferromagnetic Kagome-lattice semimetal
• High temperature fractional quantum Hall states
• CsV${}_3$Sb${}_5$: a ${\mathbb{Z}}_2$ topological kagome metal with a superconducting ground state
• Massive Dirac fermions in a ferromagnetic kagome metal
• Magnetic Weyl Semimetal Phase in a Kagome Crystal
• Discovery of unconventional chiral charge order in kagome superconductor KV3Sb5
• Dirac fermions and flat bands in the ideal kagome metal FeSn
• Fermi-arc diversity on surface terminations of the magnetic Weyl semimetal Co3Sn2S2
• Large intrinsic anomalous Hall effect in half-metallic ferromagnet Co3Sn2S2 with magnetic Weyl fermions
• Roton pair density wave and unconventional strong-coupling superconductivity in a topological kagome metal
• Herbertsmithite and the Search for the Quantum Spin Liquid
• Cascade of correlated electron states in a kagome superconductor CsV3Sb5
• Discovery of a quantum limit Chern magnet TbMn6Sn6
• Topological kagome magnets and superconductors
• Unconventional Fermi surface instabilities in the Kagome Hubbard Model
• Time-reversal symmetry-breaking charge order in a kagome superconductor
• Superconductivity in the ${\mathbb{Z}}_2$ kagome metal KV${}_3$Sb${}_5$
• Double superconducting dome and triple enhancement of Tc in the kagome superconductor CsV3Sb5 under high pressure
• Three-dimensional charge density wave and robust zero-bias conductance peak inside the superconducting vortex core of a kagome superconductor CsV${}_3$Sb${}_5$
• Evidence for a Gapped Spin-Liquid Ground State in a Kagome Heisenberg Antiferromagnet
• Discovery of charge density wave in a correlated kagome lattice antiferromagnet
• Sublattice Interference in the Kagome Hubbard Model
• Orbital-selective Dirac fermions and extremely flat bands in frustrated kagome-lattice metal CoSn
• Intertwined magnetism and charge density wave order in kagome FeGe
• Quantum states and intertwining phases in kagome materials
• Doped Kagome System as Exotic Superconductor
• Pressure-induced Superconductivity at 32 K in MoB2
• Charge density wave orders and enhanced superconductivity under pressure in the kagome metal CsV3Sb5
• Electronic nematicity without charge density waves in titanium-based kagome metal
• Non-trivial band topology and orbital-selective electronic nematicity in a new titanium-based kagome superconductor
• Magnetic-field control of topological electronic response near room temperature in correlated Kagome magnets
• Evidence of orbit-selective electronic kagome lattice with planar flat-band in correlated paramagnetic YCr6Ge6
• Superconductivity arising from pressure induced Lifshitz transition in Rb${}_2$Pd${}_3$Se${}_4$ with kagome lattice