Character of holes in LixNi1-xO and their magnetic behavior
Abstract
Using oxygen K-edge x-ray absorption spectroscopy we show that the holes compensating the Li1+ impurity charge in LixNi1-xO are located primarily in the O 2p states rather than in the conventionally assumed Ni 3d states. These holes are bound to the Li1+ impurities forming states in the NiO band gap. We also argue that these O 2p holes have a very large antiferromagnetic exchange interaction with neighboring Ni2+ (d8) spins, which makes them appear like low-spin Ni3+ states in macroscopic magnetic measurements. This is similar to what could be happening in the Cu-based high-Tc superconductors.
- Publication:
-
Physical Review Letters
- Pub Date:
- January 1989
- DOI:
- 10.1103/PhysRevLett.62.221
- Bibcode:
- 1989PhRvL..62..221K
- Keywords:
-
- 78.70.Dm;
- 75.30.Et;
- X-ray absorption spectra;
- Exchange and superexchange interactions