Current-induced colossal electroresistance in p-n heterostructure of La0.67Ca0.33MnO3-δ and Nb-doped SrTiO3 -: art. no. 072506

We report the colossal negative electroresistance (ER) in the p-n heterostructure of La0.67Ca0.33MnO3-delta (LCMO) and Nb-doped SrTiO3. For a vacuum-annealed sample, a maximum ER of 4x10(4)% can be reached by 1 mA current and magnetic field has remarkable influence on the ER of the sample. It is interesting that the magnetoresistance of the heterostructure can also be tuned by electric current. The results were explained by the current shunting model. In this scenario, the current shunting is determined by the resistance of LCMO and the junction resistance. On the other hand, the resistance of LCMO and the junction resistance are also affected by current. The interaction of these factors can tune the electrical transport of the heterostructure dramatically. This work shows that manganites combined with other materials can result in some interesting properties that may have potential applications. (C) 2005 American Institute of Physics.