Metal-insulator transition and giant magnetoresistance in La1-xMnO3-delta thin films and superlattices

The first fabrication of self-doped La1-xMnO3-delta films which are unique among the other La(1-x)M(x)MnO(3) (M = Ca, Ba and Pb) thin films showing giant magnetoresistance is reported. Ag-doped La0.7MnO3-delta films were grown on LaAlO3[100] substrates. These films show ferromagnetic and metal-insulator transition at 220 K and exhibit giant magnetoresistance (GMR) with Delta R/R(o) = 85% and Delta R/R(H) > 550%. Without silver addition these self-doped films are non-magnetic, Enhancement in GMR up to 8% has been observed in superlattices having alternate magnetic and non-magnetic La1-xMnO3-delta layers