Electronic Self-Organization in the Single-Layer Manganite Pr_1-xCa_1+xMnO₄

We use neutron scattering to investigate the doping evolution of the magnetic correlations in the single-layer manganite Pr_1-xCa_1+xMnO₄, away from the x=0.5 composition where the CE-type commensurate antiferromagnetic (AF) structure is stable. We find that short-range incommensurate spin correlations develop as the system is electron doped (x<0.5), which coexist with the CE-type AF order. This suggests that electron doping in this system induces an inhomogeneous electronic self-organization, where commensurate AF patches with x=0.5 are separated by electron-rich domain walls with short-range magnetic correlations. This behavior is strikingly different than for the perovskite Pr_1-xCa_xMnO₃, where the long-range CE-type commensurate AF structure is stable over a wide range of electron or hole doping around x=0.5.