Paired and Unpaired Charge Stripes in the Ferromagnetic Phase ofLa0.5Ca0.5MnO3
The mysterious coexistence of ferromagnetism and charge ordering in ${\mathrm{La}}_{0.5}{\mathrm{Ca}}_{0.5}{\mathrm{MnO}}_{3}$ is found to result from an inhomogenous spatial mixture of incommensurate charge-ordered and ferromagnetic charge-disordered microdomains with a size of 20--30 nm. Furthermore, high resolution lattice images of the incommensurate charge-ordered microdomains indicate a charge-ordered state with a fine mixture of paired and unpaired Jahn-Teller distorted ${\mathrm{Mn}}^{3+}$ stripes. We propose that the unpaired ${\mathrm{Mn}}^{3+}$ stripes arise from disordering of the ${d}_{{z}^{2}}$ orbitals. These results demonstrate a dramatic case of microscopic-scale electronic phase separation.