Lattice thermal conductivity is a sensitive probe of distortions of the translational invariance of crystalline materials. Crossplane thermal conductivity, $\kappa \left(T\right)$, was studied by the 3ω technique in superlattices, comprising orthorhombic charge/orbital ordered manganite ${\mathrm{Pr}}_{0.7}{\mathrm{Ca}}_{0.3}{\mathrm{MnO}}_3$ and cubic ${\mathrm{SrTiO}}_3$. The manganite/titanite superlattices show a peak in $\kappa \left(T\right)$ just above the charge order transition temperature $T_{\mathrm{CO}}\sim 240\mathrm{K}$ with a pronounced thermal hysteresis. This ordering peak in $\kappa \left(T\right)$ is successively suppressed with decreasing layer thickness. Our results demonstrate a minor effect of the interface density on $\kappa$, primarily visible below $T_{\mathrm{CO}}$. In contrast, much higher changes in $\kappa \left(T\right)$ evolve close to $T_{\mathrm{CO}}$, due to interface-induced effects on charge and orbital ordering. Our results suggest that the ordering peak in $\kappa \left(T\right)$ is a result of lattice softening above the phase transition which is modified by thickness-dependent misfit strain.

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• Thermal conductivity
• Interfaces
• Strongly correlated systems
• Electron microscopy