μSR study of short-range magnetic order in the paramagnetic regime of ErCo2

Zero-field muon spin relaxation spectroscopy (mu SR) measurements in the paramagnetic phase of ErCo2 ferrimagnetic system are reported. Previous experimental studies using macro-and microscopic techniques led to the identification of magnetic short-range correlations between the Co atoms in the paramagnetic state of this material. The analysis of mu SR spectra recorded on ErCo2 well above T-c indicates two dynamical magnetic processes characterized by remarkably different relaxation rates: a slow-relaxing signal, which quantitatively coincides with previous mu SR studies on ErAl2, and fast-relaxing signal, which can be ascribed to the Co short-range correlated regions observed above Tc. Moreover, the mu SR technique provides information on the thermal dependence of Co correlated regions at true zero field. These findings shed light on the dynamical nature of the clustered phase developing in the paramagnetic state of ErCo2.