High-Tc Superconductivity with Tc = 52 K under Antiferromagnetic Order in Five-layered Cuprate Ba2Ca4Cu5O10(F,O)2 with TN = 175 K: 19F- and Cu-NMR Studies
Abstract
We report on the observation of high-Tc superconductivity (SC) emerging with the background of an antiferromagnetic (AFM) order in the five-layered cuprate Ba2Ca4Cu5O10(F,O)2 through 19F-NMR and zero-field Cu-NMR studies. The measurements of spectrum and nuclear spin-lattice relaxation rates 19(1/T1) of 19F-NMR give convincing evidence for the AFM order taking place below TN = 175 K and for the onset of SC below Tc = 52 K, hence both coexisting. The zero-field Cu-NMR study has revealed that AFM moments at Cu sites are 0.14 muB at outer CuO2 layers and 0.20 muB at inner ones. We remark that an intimate coupling exists between the AFM state and the SC order parameter below Tc = 52 K; the spin alignment in the AFM state is presumably changed in the SC-AFM mixed state.