Low‐Field Magnetoresistance Effect in Core–Shell Structured La_0.7Sr_0.3CoO₃ Nanoparticles

Abstract Core–shell structured La_0.7Sr_0.3CoO₃ nanoparticles are synthesized and their magnetic and magneto‐transport properties are investigated. In these core–shell La_0.7Sr_0.3CoO₃ nanoparticles, the cores are single‐crystalline and ferromagnetic, whereas the shells are noncrystalline and predominantly paramagnetic. Moreover, the insulating‐like shells can serve as a good spin tunneling barrier. Therefore, in such a special core–shell structure, the spin‐polarized interparticle tunneling is improved due to the existence of shells, which thus induces an enhanced low‐field magnetoresistance effect.