Phase diagram of low doping manganites

We present a study performed on several LaMnO3+x/2 compositions. Detailed a nalysis around x = 0.09 detects phase separation between a higher transitio n, T-c, and a lower one T-N, with coexisting fluctuating and magnetically o rdered clusters (the Neel point, T-N, being the onset of an inhomogeneous n on-collinear antiferromagnetic order detected by neutrons). The ordered clu sters give rise to an extremely fast, static Kubo-Toyabe muon depolarizatio n, while mixed static and dynamic local fields are detected inside the fluc tuating clusters. Below T-N precession frequency lines are resolved, despit e the huge broadening introduced by localized Mn4+ ordered moments. A phase diagram is obtained and briefly discussed in the context of electronic pha se separation. (C) 2000 Elsevier Science B.V. All rights reserved.