  Precise neutron-scattering experiments on
La$_{1.88-y}$Sr$_{0.12+y}$Cu$_{0.99}$R$_{0.01}$O$_4$ ($y$=0 for R=Cu, Zn and
$y$=0.01 for R=Ga, Fe) were performed to examine the stability of stripe order
in cuprate oxides through impurity substitution effects. For all the
impurity-substituted samples a static charge-density-wave order similar to that
reported in the low-temperature-tetragonal phase (LTT) was discovered in the
low-temperature-orthorhombic (LTO) phase for the first time. Fe substitution
significantly enhanced both the charge- and spin-density-wave orders. These
results indicate that dynamical charge stripes can be stabilized into static
ones around the Cu-site defects regardless of the type of crystal structure.
Additionally, large magnetic moments at the Cu-site may induce a decrease in
the Cu spin fluctuations around the defects, which in turn, enhances the static
charge-density-wave order.
