  Strain engineering of functional properties in epitaxial thin films of
strongly correlated oxides exhibiting octahedral-framework structures is
hindered by the lack of adequate misfit relaxation models. Here we present
unreported experimental evidences of a four-stage hierarchical development of
octahedral-framework perturbations resulting from a progressive imbalance
between electronic, elastic and octahedral tilting energies in La0.7Sr0.3MnO3
epitaxial thin films grown on SrTiO3 substrates. Electronic softening of the Mn
- O bonds near the substrate leads to the formation of an interfacial layer
clamped to the substrate with strongly degraded magnetotransport properties,
i.e. the so-called dead layer, while rigid octahedral tilts become relevant at
advanced growth stages without significant effects on charge transport and
magnetic ordering.
