Heat Stagnation of Dy-Doped La2/3Ca1/3MnO3 Manganese Oxides in the Measurement Process of Warming and Cooling

摘要

(La_(1–x )Dy_(x ))_(2/3)Ca_(1/3)MnO_(3) samples with the perovskite structure were prepared by the sol–gel method, and the R –T curves of the samples in 0–3000 Gs magnetic field during warming and cooling processes were compared. It is found that the transition temperature (T _(c)) of the samples decreases and peak resistance (R _(P)) of the samples increases with the increase of Dy concentration in the same magnetic field. In addition, for the samples with the same Dy concentration, T _(c) of the samples increases and magnetoresistance (MR) of the samples decreases with the increase of the magnetic field, and the increase of T _(c) as well as the decrease of resistance is more obvious during the cooling process than those during the warming one. Besides, the variation of MR during the cooling process is also larger than that during the warming one.