Critical Magnetism of the CMR Ruddlesden-Popper Manganite La1.2Sr1.8Mn2O7

Abstract

ABSTRACTWe present a thermodynamic study of the critical magnetic properties of La1.2Sr1.8Mn2O7, including the determination of the fundamental characteristics of a magnetic system: anisotropy, critical exponents and crossovers in the vicinity of the Curie temperature, TC∼108K. It appears that two-dimensional correlations above TC do not spread very fast, and that thus the critical fluctuations regime occurs in a moderately narrow temperature range, assessing the three- dimensional nature of the ferromagnetic ordering.