Commensurate dynamic magnetic correlations in La2Cu0.9Li0.1O4

When sufficient numbers of holes are introduced into the two-dimensional Cu O2 square lattice, dynamic magnetic correlations become incommensurate with underlying lattice in all previously investigated La(2-x)A(x)Cu(1-z)B(z)O( 4+y) (A = Sr or Nd, B = Zn) including high T-c superconductors and insulato rs, and in bilayered superconducting YBa2Cu3O6.6 and Bi2Sr2CaCu2O8. Magneti c correlations also become incommensurate in structurally related La2NiO4 w hen doped with Sr or O. We report an exception to this so-far well-establis hed experimental "rule" in La2Cu1-zLizO4 in which magnetic correlations rem ain commensurate.