Electronic structure reconstruction and possible charge-transfer behavior in Sm-substituted trilayer nickelates

Abstract

The trilayer Ruddlesden-Popper-type rare-earth nickelates, Ln4Ni3O10, have attracted considerable attention because of their superconductivity and density-wave (DW) behavior. The investigation of the interaction among these properties demands lattice and electron structure modulation. In this work, a series of Sm-doped samples, i.e. SmxPr4-xNi3O10 (x = 0.1–0.5) were synthesized in order to tune the lattice and electron structure. A critical point was observed at x = 0.2, where the magnetic parameters remained nearly unchanged across the DW transition, and an associated jumping point was also observed in the lattice parameters. Based on analyses of x-ray diffraction, x-ray photoelectron spectroscopy and heat-capacity data, we present an possible electron-transfer mechanism from Sm ions to Ni ions. Moreover, the Sm-doping and the electron-transfer process may lead to a possible electronic structure reconstruction in this sample series.