Colossal magnetoresistance in screen printed La0.67Ca0.33MnO3 thick films

Thick films of La0.67Ca0.33MnO3 were fabricated on (100) oriented single cr ystal LaAlO3 (LAO), yttria stabilized zirconia (YSZ) and on polycrystalline Al2O3 by a screen printing technique. A range of sintering conditions were explored with temperature of 1200, 1300 and 1400 degrees C, and in air, ox ygen and nitrogen atmospheres. Magnetic and DC resistance properties were m easured on all films. The so-called 'colossal magnetoresistance' (CMR) beha viour was found to occur for films on all substrates but for specific prepa ration conditions. The salient feature of the CMR observed in these thick f ilms is that MR is not limited to a small temperature window near the metal -insulator transition (M-I), T-p1. The MR peak is very broad and for some f ilms a temperature independent CMR is observed at temperatures below T-p1. Several repeat films were made and the reproducibility of the results obtai ned in the first batch was confirmed. (C) 2000 Elsevier Science S.A. All ri ghts reserved.