Observation of Magnetic Ordering in La2-xSrxCuO4aroundx=0.115–La-NQR Study–

Abstract
The nuclear quadrupole resonance (NQR) study of 139 La in La 2- x Sr x CuO 4 was systematically carried out in the Sr-content range from 0.085 to 0.15 at 1.4 and 4.2 K in zero field. The linewidth of the 139 La NQR spectrum for the (±1/2→±3/2) transition was found to increase especially at x =0.115, associated with the occurrence of magnetic ordering. This is hence considered to be responsible for the decrease of the superconducting transition temperature around x =0.115. Since the spectrum does not broaden with for the (±5/2→±7/2) transition down to 1.4 K, the ordered Cu-moments are considered to exist in the Cu-O 2 sheets.