Orthorhombic lattice deformation of ${\mathrm{GdSr}}_2{\mathrm{RuCu}}_2{\mathrm{O}}_8$ from high-resolution transmission electron microscopy and x-ray powder diffraction analysis

${\mathrm{GdSr}}_2{\mathrm{RuCu}}_2{\mathrm{O}}_8$ has been synthesized using a solid state reaction and has been characterized from the structural and physical points of view. The samples exhibit the well-known superconducting and magnetic behavior; in addition, an orthorhombic modification of the ${\mathrm{GdSr}}_2{\mathrm{RuCu}}_2{\mathrm{O}}_8$ lattice has been detected by both high resolution transmission electron microscopy (HRTEM) and x-ray powder diffraction (XRPD) analysis. Rietveld refinement of the XRPD data has been successfully performed in the orthorhombic $\mathrm{Pmmm}$ space group yielding an $a_0\times b_0\times c_0\left(\approx 3a_0\right)$ type cell, with octahedral ${\mathrm{RuO}}_6$ polyhedra slightly distorted and rotated around $c,$ $b,$ and $a.\mathrm{}$