Study on spin fluctuations introduced by nanoparticulation of strongly correlated electron materials

Strongly correlated (SC) manganites R1-xAxMnO3 (R: rare earth, A: alkaline earth) are known to exhibit various novel properties related to electron-spin correlation[1], such as negative magnetoresistance. Since these SC phenomena are strongly dependent on the spin arrangement, the introduction of spin fluctuations due to nanoparticle fabrication is expected to lead to the emergent properties with gigantic response, as well as new insights on the effect of spin fluctuations in SC phenomena. In fact, we have found complete suppression of the well-known charge ordering phenomena and loss of antiferromagnetic order in La1-xCaxMnO3 nanoparticles with a diameter of ~20 nm. We will therefore perform μSR studies on these nanoparticles to elucidate the temperature dependence of spatially and temporally fluctuating spin states in the nanoparticles. [1] Y. Horibe, et al, EPL100, 67007 (2012).