NMR evidence for spin fluctuations in the bilayer nickelate La3Ni2O6

We report nuclear magnetic resonance data in the bilayer nickelate La3Ni2O6. This material belongs to a family of low valence nickel oxides with square planar coordination of the Ni ions and is isoelectronic to the high temperature superconducting cuprates. Although the three layer nickelate compound exhibits a spin-state transition accompanied by antiferromagnetic order, the bilayer material shows no phase transition. The NMR data in the bilayer La3Ni2O6 reveal the presence of antiferromagnetic spin fluctuations down to 5K that are surprisingly similar to those present in the magnetically ordered trilayer La4Ni3O8, suggesting a similar electronic structure in the paramagnetic phase of both compounds.