Digitalized magnetoresistance observed in (La,Pr,Ca)MnO3 nanochannel structures

We have examined the magnetoresistances of (La,Pr,Ca)MnO3 channel structures with different channel widths. The 500 nm channel showed an extremely sharp metallic transition from charge ordered insulator to ferromagnetic metal at low temperature, while the 10 and 1 mu m channels showed gradual metallic transitions. The sharpness of the metallic transition was increased from 1.3x10(2) T-1 in the 10 mu m channel to 3.5x10(4) T-1 in the 500 nm channel at 10 K. Such extremely sharp metallic transition can be accounted for electronic phase separation phenomena. (c) 2006 American Institute of Physics.