Paired and unpaired charge stripes in the ferromagnetic phase of La0.5Ca0.5MnO3

The mysterious coexistence of ferromagnetism and charge ordering in La0.5Ca0.5MnO3 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 Mn3+ stripes. We propose that the unpaired Mn3+ stripes arise from disordering of the d(z2) orbitals. These results demonstrate a dramatic case of microscopic-scale electronic phase separation. [S0031-9007(98)07522-X].