139La NQR study has been performed on La2NiO4+δ and La2CoO4−δ. Experimental spectra at low temperatures provided an evidence for the existence of antiferromagnetic ordering in both of them. The internal field at La site in La2NiO4+δ (19.3 kOe, ∥ c-axis) and in La2CoO4−δ (30.5 kOe, ∥ c-axis) was significantly large comparing with that in La2CuO4−δ (1.0 kOe 1 ⊥ c-axis), suggesting an importance of exchange interactions via apex oxygen atoms.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering