Large domain wall magnetoresistance up to room temperature in La_0.7Sr_0.3MnO₃ bridges with nanoconstrictions

Abstract

To obtain low field magnetoresistance (MR) in manganites, we have introduced a geometrically constrained magnetic domain wall (DW) in La0.7Sr0.3MnO3 micrometric devices. Nanoconstrictions artificially induced using high resolution e-beam lithography are shown to effectively reduce the DW width leading to strongly enhanced DW resistance. Sharp and large resistance switches result from the appearance and annihilation of the DWs. Room temperature sharp resistance switches, with a MR of 16%, are evidenced in a manganite-based device. © 2001 American Institute of Physics.