Magnetic Ni-N-Ni Centers in N-substituted NiO

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Strongly correlated oxides exhibit complex magnetic properties.
• Anion substitution is a key strategy for tuning material characteristics.
• Nickel oxide (NiO) is an important antiferromagnetic material.

Purpose of the Study:

• To investigate the effects of substituting oxygen with nitrogen in nickel oxide (NiO).
• To understand how nitrogen (N) incorporation modifies local electronic states and magnetic ordering.
• To explore the potential of N-substituted NiO for quantum technologies.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• High-resolution spectroscopy was used for experimental validation.
• Thin films of N-substituted NiO were synthesized using molecular beam epitaxy.

Main Results:

• Nitrogen (N) introduces an additional N 2p hole, modifying neighboring nickel (Ni) cation magnetic moments.
• The exchange interaction involving the N 2p hole overcomes the Ni-O-Ni superexchange.
• Formation of novel Ni-N-Ni centers with five spins was observed without perturbing the NiO lattice.

Conclusions:

• Anion substitution provides a pathway to engineer magnetism in strongly correlated oxides.
• N-substituted NiO demonstrates tunable magnetic properties with potential applications.
• This work paves the way for advanced quantum technologies utilizing magnetic materials.