Researcher from the Institute of Physics in Zagreb, in collaboration with scientists from AGH University of Krakow, Solaris synchrotron, Jagiellonian University, University of Zagreb, Institute of Nuclear Physics PN, and TU Wien, revealed the electronic structure of nickel intercalated 2H-NbS2. The collaboration between experiment and theory provided insight into the special role of magnetic Ni ions in the electronic structure. The measured spectra and theoretical analysis indicate zero algebraic sum of hybridization integrals of relevant Ni orbitals and the conducting planes of the host material.
Two-dimensional magnetic materials are of great interest from the fundamental point of view and for applications. In particular, the magnetic sublayers, introduced by intercalation into the van der Waals gaps of the host transition metal dichalcogenides, are known to produce various magnetic states depending on the choice of magnetic intercalates, with some being tunable by pressure and doping. The magnetic intercalates strongly modify the electronic coupling between layers of the host compound. Understanding the origins of such variability, starting from the underlying electronic structure, is a significant challenge. By using angle-resolved photoelectron spectroscopy (ARPES) with various photon energies and ab initio electronic structure calculations, the study revealed the electronic structure of Ni1/3NbS2.
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Image: Fig 1. Schematic image of strong spin-selective hybridization between NbS2 layers provided by intercalated magnetic ions (Ni, Co). The symmetries of dominant bridging orbitals in (a) Ni1/3NbS2 and (b) Co1/3NbS2. (c) The calculated band structures that show the type of magnetic ordering strongly affect the electronic structure. (d) The Fermi surface observed by ARPES. The magnetic fluctuations at bridging sites are prone to produce a strong electron correlation effect at the Fermi level (shallow electron pockets indicated by red arrows), which is inaccessible by DFT+U calculations.
Credit: Yuki Utsumi Boucher