Portion of the laboratory X -ray powder diffraction ( $\lambda_{\mathrm{K} \alpha 1}=1.5406 \AA$ and $\lambda_{\mathrm{K} \alpha 2}=1.5444 \AA$) profiles for $\mathrm{CaLn}_{2} \mathrm{CuTi}_{2} \mathrm{O}_{9}$ showing the evolution in temperature of the (002)-(202) reflections in Pbnm, at $770 \mathrm{K}, 1150 \mathrm{K}$ and 1450 K. The bars in the lower part of the graphics correspond to the Bragg reflections' positions; red (lower) bars indicate impurity phase (diffractometer platinum filament).
Portion of the laboratory X -ray powder diffraction ( \lambda_{\mathrm{K} \alpha 1}=1.5406 \AA and \lambda_{\mathrm{K} \alpha 2}=1.5444 \AA) profiles for \mathrm{CaLn}_{2} \mathrm{CuTi}_{2} \mathrm{O}_{9} showing the evolution in temperature of the (002)-(202) reflections in Pbnm, at 770 \mathrm{K}, 1150 \mathrm{K} and 1450 K. The bars in the lower part of the graphics correspond to the Bragg reflections’ positions; red (lower) bars indicate impurity phase (diffractometer platinum filament).