Spin-glass dynamics in interacting nanoparticle system LaCaMnO obtained by mechanochemical milling.

Spin dynamics in mechanochemically obtained nanoparticle manganite LaCaMnO was investigated in this study by means of a series of AC and DC magnetic measurements. AC susceptibility indicates the presence of sizeable interparticle interactions, yielding collective magnetic behavior. The related properties were probed by experiments in weak DC field: memory effects were analyzed in both field-cooled (FC) and zero field-cooled (ZFC) regimes, while, after ZFC aging, magnetic relaxation was recorded. The system appears to be sensitive to magnetothermal history, in analogy with spin-glass-like compounds. The analysis of the data indicates the occurrence of slow dynamics in an ensemble of strongly interacting super spins. [ABSTRACT FROM AUTHOR]