Fig. 2 |. Inelastic neutron scattering showing dynamic magnetic correlations in NaCaNi₂F₇.

Momentum and energy dependence of inelastic magnetic scattering in NaCaNi₂F₇ for the $(h,h,\ell )$ and $(h,k,0)$ scattering planes at $=1.8\mathrm{K}$. Each slice was integrated over an energy transfer range of ± 0.25 meV. No smoothing or symmetrization was applied to the data. Above energy transfers of 0.5 meV, the dynamic magnetic correlations form a ‘bow-tie’ pattern in momentum space. The sharp pinch-point-like features around (2, 0, 0) and (2, 2, 0) positions indicate that the net magnetization per tetrahedron vanishes in the Coulomb-like phase realized in NaCaNi₂F₇. Above energies of 5 meV, the scattering forms a broad continuum with no intensity around the $\mathrm{\Gamma }$ points.