Preisach analysis of (La_(0.2)Nd_(0.8))_(0.67)Pb_(0.33)MnO_3

摘要

The perovskite (La_(0.2)Nd_(0.8))_(0.67)Pb_(0.33)MnO_3 (LNPMO) with a Curie temperature T_C=220K is characterized by measuring the zero field cooled (ZFC) and field cooled (FC) moments over a wide range of temperature 2K < T < 290K in an applied field of H_a = 3978.87A/m, and also by the major hysteresis loop over the field range |H_a| ≤ 1061 kA/m at T=10K. The data analysed within the framework of a generalized Preisach model, which includes thermal fluctuations, critical effects, and a temperature-dependent distribution of free energy barriers. The analysis shows that the response function of LNPMO is dominated by the growth of the anisotropy barriers.