Phase segregation on the nanoscale in Na2C60

${\mathrm{Na}}_{2}{\mathrm{C}}_{60}$ is believed to be an electron-hole counterpart of the Mott-Jahn-Teller insulator ${A}_{4}{\mathrm{C}}_{60}$ salts. We present a study of infrared, ESR, NMR spectroscopy, x-ray diffraction, chemical composition and neutron scattering on this compound. Our spectroscopic results at room temperature can be reconciled in a picture of segregated regions of the size $3\char21{}10\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. We observe a significant insulating ${\mathrm{C}}_{60}$ phase and at least two more phases, one of which we assign to metallic ${\mathrm{Na}}_{3}{\mathrm{C}}_{60}$. The separation disappears on heating by jump diffusion of the sodium ions, which we followed by neutron scattering. Above $\ensuremath{\sim}460\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ we see infrared spectroscopic evidence of a Jahn-Teller distorted ${\mathrm{C}}_{60}^{2\ensuremath{-}}$ anion.