Publication details
Mechanism of intermetallic charge transfer and bond disproportionation in BiNiO3 and PbNiO3 revealed by hard x-ray photoemission spectroscopy
| Authors | |
|---|---|
| Year of publication | 2024 |
| Type | Article in Periodical |
| Magazine / Source | Physical Review B |
| MU Faculty or unit | |
| Citation | |
| web | https://journals.aps.org/prb/abstract/10.1103/PhysRevB.109.205131 |
| Doi | http://dx.doi.org/10.1103/PhysRevB.109.205131 |
| Keywords | Metal-insulator transition; Perovskites; Transition metal oxides; Density functional theory; Dynamical mean field theory; Hard x-ray photoelectron spectroscopy; Photoemission spectroscopy |
| Description | Perovskites with Bi or Pb on the A site host a number of interesting and yet to be understood phenomena such as negative thermal expansion in BiNiO3. We employ hard x-ray photoemission spectroscopy of Ni 2p core level as well as valence band to probe the electronic structure of BiNiO 3 and PbNiO3. The experimental results supported by theoretical calculations using dynamical mean-field theory reveal essentially identical electronic structure of the Ni-O subsystem typical of Ni2+ charge-transfer insulators. The two materials are distinguished by filling of the Bi(Pb)-O antibonding states in the vicinity of the Fermi level, which is responsible for the Bi disproportionation in BiNiO3 at ambient pressure and absence of similar behavior in PbNiO3. The present experiments provide evidence for this conclusion by revealing the presence/absence of Bi/Pb 6s states at the top of the valence band in the two materials. |