  The structural and microstructural properties of the
Sm(Fe1-xRux)As(O0.85F0.15) system were investigated by means of high-resolution
synchrotron X-ray powder diffraction between 10 K and 300 K. The tetragonal to
orthorhombic structural transition temperature decreases with the increase of
the Ru content and the symmetry breaking is completely suppressed around x ~
0.38. By combining the present results with previous magnetic and resistivity
measurements, a phase diagram for the Sm(Fe1-xRux)As(O0.85F0.15) system has
been drawn.
