Hole concentration dependence of the magnetic moment in superconducting and insulatingLa2−xSrxCuO4

Recent neutron-scattering measurements on the ${\mathrm{La}}_{2-x}{\mathrm{Sr}}_x{\mathrm{CuO}}_4$ system have revealed a drastic change of the incommensurate static-spin correlations from diagonal in the insulating region to parallel in the superconducting region. We report the doping dependence of the ordered magnetic moment for the hole concentration region $0.03<~x<~0.12,$ focusing on the relationship between the static magnetism and the superconductivity. The elastic magnetic cross-section decreases monotonically with increasing x for $0.03<~x<~\mathrm{0.07.}$ We find that the ordered magnetic moment $\mu$ varies from $\sim 0.18{\mu }_B/\mathrm{Cu}\mathrm{}(x=0.03\mathrm{})\mathrm{}$ to $\sim 0.06{\mu }_B/\mathrm{Cu}\mathrm{}(x=0.07\mathrm{}).$ No significant anomaly is observed at the insulator-superconductor boundary $(x\sim 0.055).$ The elastic magnetic cross-section is enhanced in the vicinity of $x=0.12\mathrm{}$ where resolution-limited width peaks are observed in neutron-scattering measurements and where the apparent magnetic and superconducting transitions coincide.