The authors have established that at least 10% of the copper atoms in La1.825Sr0.175CuO4 can be replaced by iron without altering the type of structure. The orthorhombic-tetragonal transition point rises in that case, and that should raise the temperature of the anomalies of the physical parameters (such as the acoustic properties). When the iron content is increased, the lattice expands as a whole, but very anisotropically, with compression along the c-axis. Iron apparently has a similar influence for other strontium concentrations in La2-xSrxCu1-yFeyO4. The results might be useful in interpretation of Mossbauer studies of superconductors La2-xSrxCuO4 on isotope 57Fe.