Triggering a Metal-insulator Transition in La(0.8)Sr(0.2)MnO(3) Nanoparticle-decorated Carbon Nanotubes

We have studied the magnetic and the electric properties of La(0.8)Sr(0.2)MnO(3) (LSMO) nanoparticle-decorated carbon nanotubes (CNTs). The magnetic susceptibility showed a paramagnetic - superparamagnetic phase transition at T(sp) similar to 200 K with a blocking temperature of T(B) similar to 120 K, which can be attributed to the LSMO nanoparticles. At T(sp), the charge transport taking place through the CNTs network showed a metal-insulator transition (MIT) characteristic of the LSMO nanoparticles, indicating a concomitant MIT in the CNTs triggered by the LSMO nanoparticles. In the metallic phase, the charge transport appears to be dominated by a 2D weak localization effect, which at temperatures below T(B) was seen to be somewhat suppressed by the internal field. At temperatures below 50 K, a Kondo effect dominates the electric and the magnetic properties.