Magnetism dynamics in polycrystalline Pr-doped manganites: role of the phase separation

Mixed valence manganites often have complex phase diagrams where different phases can coexist. Proper stoichiometry allows the coexistence of ferromagnetic metal and antiferromagnetic charge ordered insulator phases in (La,Pr,Ca)MnO₃ (LPCMO). The phase separation in LPCMO has two behaviors: a fluid-like phase separation (FPS)—at intermediate temperatures—where the phase morphology evolution depends strongly on external stimuli, and a static phase separation (SPS)—at lower temperatures—that has a glass-like behavior. By performing ferromagnetic resonance and AC susceptibility measurements, we demonstrate that the magnetism dynamics of polycrystalline manganite La_5/8-xPr_xCa_3/8MnO₃ pellets are driven by the phase separation. Our results provide an insight into the mechanism behind the FPS-to-SPS transition in the LPCMO system.