Suppression of structural and magnetotransport transitions in compressed Pr0.5Sr0.5MnO3 thin films resulting in colossal magnetoresistance effect

Thin films of Pr0.5Sr0.5MnO3 have been deposited on [100]-LaAlO3 using lase r ablation. In contrast to the bulk compounds, such films do not exhibit an y structural and magnetotransport transitions versus temperature; more part icularly the A-type antiferromagnetic phase with the Fmmm structure which e xists in the bulk below T-N = 135 K is suppressed, and the film is an insul ator in the absence of a magnetic field. However a colossal magnetoresistan ce effect is observed, with resistance ratios much larger than in the bulk. These differences with respect to the bulk, are explained by the presence of substrate-induced strains. (C) 2001 American Institute of Physics.