Strain effect and current-induced electroresistance in epitaxial thin films of La0.9Sr0.1MnO3

La0.9Sr0.1MnO3 thin films with the thickness ranging from 10 to 100 nm have been fabricated by pulsed laser deposition. An insulator-metal transition can be developed with decreasing the thickness of film. The strain compression of the lattice induced by substrate may strongly influence the static Jahn-Teller distortion and cause an increase of double exchange interaction. Subsequently, attention was focused on the influence of a dc current on the resistance of these epitaxial thin films in the absence of a magnetic field. A significant reduction of the peak resistances reaches ∼4% and ∼42% for two samples with different thicknesses upon a current density up to 100 KA/cm2, respectively. The influence of strain effect on the electrical transport was studied. The strain may stabilize the multiphase coexistence and then suppress the current-induced electroresistance in the system.