  Understanding the role of disorder and the correlations that exist within it,
is one of the defining challenges in contemporary materials science. However,
there are few material systems, devoid of other complex interactions, which can
be used to systematically study the effects of crystallographic conflict on
correlated disorder. Here, we report extensive diffuse x-ray scattering studies
on the epitaxially stabilised alloy $\mbox{U}_{1-x}\mbox{Mo}_x$, showing that a
new form of intrinsically tuneable correlated disorder arises from a mismatch
between the preferred symmetry of a crystallographic basis and the lattice upon
which it is arranged. Furthermore, combining grazing incidence inelastic x-ray
scattering and state-of-the-art ab initio molecular dynamics simulations we
discover strong disorder-phonon coupling. This breaks global symmetry and
dramatically suppresses phonon-lifetimes compared to alloying alone, providing
an additional design strategy for phonon engineering. These findings have
implications wherever crystallographic conflict can be accommodated and may be
exploited in the development of future functional materials.
