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Chain-oxygen ordering in twin-free Y Ba 2 Cu 3 O 7 − δ single crystals driven by<…

2005; American Physical Society; Volume: 72; Issue: 5 Linguagem: Inglês

10.1103/physrevb.72.052501

1550-235X

Hye-Won Seo, Q. Y. Chen, M. N. Iliev, T. H. Johansen, Nikolay Ivanov Kolev, U. Welp, C. Wang, Wei‐Kan Chu,

Magnetic properties of thin films

We have examined the effects of 20 keV electron irradiation on [-Cu(1)-O(1)-]n chain oxygen arrangements in oxygen deficient but otherwise twin-free YBa2Cu3O6+x single crystals. Comparison of polarized Raman spectra of non-irradiated and irradiated areas provides evidence that electron bombardments instigate the collective hopping of oxygen atoms either from an interstitial at O(5) site to a vacant O(1) chain site or by reshuffling the chain segments to extend the average length of chains without changing the overall oxygen content. This oxygen ordering effect, while counter-intuitive, is analogous to that found in the photoexcitation induced ordering in which temporal charge imbalance from electron-hole pair creation by inelastic scattering of incident electrons causes a local lattice distortion which brings on the atomic rearrangements.