Local symmetry of copper sites inLa2−xSrxCuO4

Abstract
Nuclear quadrupole and magnetic resonances of copper ions in La1.84 Sr0.16 CuO4 have been performed at temperatures between 300 and 5 K. The analysis of the spectra shows that there are two electronically distinct copper sites for which the symmetry of the electric-field-gradient tensors is uniaxial with the principal axis along the crystal c axis. This result constrains possible structural models.