  The local environment and oxidation state of Mn impurity in strontium
titanate doped with 3% Mn were studied by X-ray absorption fine structure
spectroscopy. The influence of the preparation conditions on the incorporation
of the impurity into the $A$ and $B$ sites was studied. It was established that
Mn ions substituting for Ti are in the Mn$^{4+}$ oxidation state and on-center.
Mn ions substituting for Sr are in the Mn$^{2+}$ oxidation state, are
off-center and displaced from the lattice sites by $\sim$0.32 {\AA}. It was
demonstrated that studies of the X-ray absorption near-edge structure can be
used to determine the concentration ratio of Mn atoms located at the $A$ and
$B$ sites.
