We have used x-ray diffraction and Raman spectroscopy over a broad temperature range $(90\phantom{\rule{0.3em}{0ex}}\mathrm{K}\ensuremath{\leqslant}T\ensuremath{\leqslant}900\phantom{\rule{0.3em}{0ex}}\mathrm{K})$ to study the structural and dynamical behavior of ${[{\mathrm{PMN}}_{(1\ensuremath{-}x)\ensuremath{\Lambda}}∕{(\mathrm{Pb}\mathrm{Ti}{\mathrm{O}}_{3})}_{x\ensuremath{\Lambda}}]}_{10}$ superlattices $(x=0.2,0.5,0.8)$ (where PMN is $\mathrm{Pb}{\mathrm{Mg}}_{1∕3}{\mathrm{Nb}}_{2∕3}{\mathrm{O}}_{3}$), which were epitaxially grown with a nominal wavelength $\ensuremath{\Lambda}$ of $130\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$ by pulsed laser deposition on MgO substrates buffered with ${\mathrm{La}}_{0.5}{\mathrm{Sr}}_{0.5}\mathrm{Co}{\mathrm{O}}_{3}$. We present a comparison of the results obtained on these superlattices with the temperature evolution of three fictitious superlattices constructed using the temperature-dependent data obtained on individual $\mathrm{Pb}\mathrm{Ti}{\mathrm{O}}_{3}$ and $\mathrm{Pb}{\mathrm{Mg}}_{1∕3}{\mathrm{Nb}}_{2∕3}{\mathrm{O}}_{3}$ epitaxial thin films. From this study, we conclude that the PMN layers in superlattices retain the structural characteristics, including the tetragonal distortion, of relaxor thin films. The $\mathrm{Pb}\mathrm{Ti}{\mathrm{O}}_{3}$ layers exhibit in-plane polar orientation at all temperatures. X-ray diffraction shows the stabilization, due to biaxial stress, of the ferroelectric order up to at least $873\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ in the $\mathrm{Pb}\mathrm{Ti}{\mathrm{O}}_{3}$ layers (${T}_{C}=763\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ in bulk). The tetragonal symmetry and ferroelectric order of the $\mathrm{Pb}\mathrm{Ti}{\mathrm{O}}_{3}$ layers, as well as the relaxorlike behavior of the PMN layers, are confirmed by Raman spectroscopy.