F 19 NMR investigation of the iron pnictide superconductor LaFeAsO0.89F0.11

We report on F 19 nuclear magnetic resonance (NMR) investigation of the high-temperature superconductor LaFeAsO0.89F0.11 (Tc∼28 K). We demonstrate that low-frequency spin fluctuations exhibit pseudogap behavior above Tc. We also deduce the London penetration depth λ from NMR line broadening below Tc.