1998/12/30 by A. Lanzara, N. L. Saini, Lanzara, A. +13
Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #FOS: Physical sciences #High-pressure geophysics and materials #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.cond-mat/9812425
4 pages, 3 eps figures, removed references in abstract
openalex publication_date 1998/12/30 · arxiv created 1999/01/05 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Recently a growing number of experiments have provided indications of the key role of polarons (composite particles formed by a charge strongly coupled with a local lattice deformation) in doped perovskites, hosting colossal magnetoresistance (CMR) and high Tc superconductivity. While the role of polarons is generally recognized in manganites due to the large amplitude of the local lattice deformation, the scientific debate remains open on the cuprates where the lattice deformation is smaller and the anomalous normal metallic phase becomes complex due to the coexistence of polarons with itinerant carriers. Moreover the segregation of polarons and itinerant charges in different spatial domains forming lattice-charge stripes as well as the slow dynamic 1D spin fluctuations have been observed. The debate on the driving force for the stripe formation remains object of discussion since it could be purely due to electronic interactions and/or due to strong electron-lattice (polaronic) interactions. In order to explore the important role of the latter in stripe charge segregation, we have studied isotope effects on the dynamical lattice fluctuations and polaron ordering temperature. Here we report a compelling evidence for a huge isotope effect on local lattice fluctuations of La(2-x)Sr(x)CuO(4) high Tc superconductor by x-ray absorption spectroscopy, a fast (~10^(-15) sec) and local probe (~5 A). Upon replacing 16O with 18O, the characteristic temperature T* for polaron ordering in La(1.94)Sr(0.06)CuO(4) increases from about 110 K to 170 K.