Copper NMR and NQR in La2-xSrxCuO4–No Evidence for Coexistence of Magnetic Ordering and Superconductivity down to 1.3 K

Abstract
Nuclear magnetic/quadrupole resonance (NMR/NQR) has been observed for the Cu nuclei in La 2- x Sr x CuO 4 . NMR measurements have been carried out for the powdered sample whose c axes are aligned. No evidence for magnetic ordering was observed down to 1.3 K. Instead, the existence of two sets of 63/65 Cu resonances due to nonequivalent Cu sites has been concluded from the results of spectrum and relaxation measurements at low temperatures. These resonances are ascribed to the effect of the charge differentiation introduced by the substitution of Sr for La.