Skip to main content
Research Highlight | Materials Science

Cuprate-like orbital state in a metallic layered nickelate

In a study published in Nature Physics, researchers reported that the low-valent, quasi-two-dimensional trilayer compound Pr4Ni3O8 avoids a charge-stripe-ordered phase previously reported for La4Ni3O8, leading to a metallic ground state.

Scientific Achievement

We have discovered that the layered nickelate Pr4Ni3O8 is metallic, with Ni 3d states of x2-y2 character that are hybridized with oxygen ligands.

Significance and Impact

Our result means that Pr4Ni3O8 corresponds to the overdoped, metallic regime of the cuprates, and suggests electron doping as a route to a nickelate superconductor.

Research Details

  • X-ray absorption spectroscopy (XAS) establishes strong x2-y2 Ni 3d-orbital polarization in bulk single crystals of R4Ni3O8 (R=La, Pr).
  • DFT calculations corroborate XAS measurements to establish that Ni adopts a low-spin state with strong Ni 3d — O 2p hybridization. 
  • While the related La4Ni3O8 is a charge-ordered insulator, both transport and heat capacity data reveal that Pr4Ni3O8 is metallic, a necessary condition for potential cuprate-like superconductivity.

DOI10.1038/nphys4149

Download this highlight

Argonne National Laboratory seeks solutions to pressing national problems in science and technology by conducting leading-edge basic and applied research in virtually every scientific discipline. Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://​ener​gy​.gov/​s​c​ience.