Emergent Order in the Kagome Ising Magnet Dy$_{3}$Mg$_{2}$Sb$_{3}$O$_{14}$

The 3:1 cation ordered pyrochlore Dy$_{3}$Mg$_{2}$Sb$_{3}$O$_{14}$ forms a magnetic lattice of layered two-dimensional (2D) Kagome sheets, comprised of corner sharing triangles. As in the 3D spin-ice analogue, Dy$_{2}$Ti$_{2}$O$_{7}$, the Dy$^{3+}$ spins have Ising like behaviour. Here, we show that the layered Ising magnet Dy$_{3}$Mg$_{2}$Sb$_{3}$O$_{14}$ hosts an emergent order predicted theoretically for individual kagome layers of in-plane Ising spins. Neutron-scattering and bulk thermomagnetic measurements, supported by Monte Carlo simulations, reveal a phase transition at $T$* $=$ 0.3 K from a disordered spin-ice like regime to an "emergent charge ordered" state in which emergent charge degrees of freedom exhibit three-dimensional order while spins remain partially disordered. Our results establish Dy$_{3}$Mg$_{2}$Sb$_{3}$O$_{14}$ as a tuneable system to study interacting emergent charges arising from kagome Ising frustration.