Resistance steps and large magnetoresistive effect in La0.67 Sr0.33 MnO3 nanoconstriction array

Abstract

The transport properties of La0.67 Sr0.33 MnO3 (LSMO) nanoconstriction array under large applied current with current density in the order of 105 A cm2 have been investigated. A series of resistance steps were observed at 78 K with applied current up to 1.0 mA. The critical current value at which resistance jump occurs varied with temperatures and the applied magnetic fields. The observation was attributed to the local heating induced phase transition at the section of nanoconstrictions where phase separation is dominant. A large low field magnetoresistive ratio of 52.2% was achieved at 78 K with the magnetic field up to 3000 Gauss when the biased current was set to 0.34 mA. This LSMO nanoconstriction array shows promise in the application of magnetic field sensors. © 2005 American Institute of Physics.