Field effect on phase segregation in the electron-doped mixed-valence manganites near a structural instability

Abstract

The rich and peculiar macro- and microscopic phenomenology observed in the electron-doped region of the Sm-Ca phase diagram of manganites can be found in the unique and fascinating compound ${\mathrm{Sm}}_{0.15}{\mathrm{Ca}}_{0.85}{\mathrm{MnO}}_{3}.$ We report the existence of nano- and microscopic phase segregation above and below ${T}_{N}\ensuremath{\approx}112\mathrm{K}.$ The very different nature of the coexisting phases and the field and temperature dependencies are explained considering the interplay of magnetic and structural correlations, which give rise to different structural and magnetic ground states, close in energies $(P\ensuremath{-}Pnma,$ $G+F\ensuremath{-}Pnma,$ $G\ensuremath{-}Pnma,$ ${C\ensuremath{-}P2}_{1}/m).$