Giant magnetoresistance in perovskite-like La0.6Nd0.2Ca0.2MnO3 thin films

The polycrystalline La0.6Nd0.2Ca0.2MnO3 thin films have been deposited at 800 C on LaAlO3 substrate using pulsed laser deposition. The magneto resistance (MR = DeltaR/R-(n=0)) of a thin film at H = 4 T initially increases with decreasing temperature attaining a peak value of 80% closer to the ferromagnetic transition temperature at 150 K and then shows a gradual increase in MR leading to saturation at lower temperatures below 75 K up to 10 K with an MR value of 95%. The bulk sample exhibits maximum MR value of 40% in the temperature range of 50-150 K, which is 50% smaller than the thin film MR values. In the film, the insulator-to-metal transition and the saturation magnetization are considerably lower compared to a bulk sample, inspite of both having the same Curie temperature. The thin film exhibits a markedly different temperature dependence in zero-field-cooled and field-cooled magnetization at 0.005 T in comparison to the bulk sample possibly due to the presence of domain walls. (C) 2002 Published by Elsevier Science B.V.