Seminars Archive

Statistical physics of nanoscale lattice fluctuations controlling material functionalities unveiled by scanning nano XRD.

Abstract
In the seventies it was clear that the use of high brilliance synchrotron radiation beams will have allowed one the major breakthroughs in material science : micro X-ray diffraction μXRD. In these last 40 years μXRD at dedicated beam lines at dedicated SR sources has been widely applied for solving the structure of very small microscopic crystalline samples. In these last 4 years we have used scanning μXRD (SμXRD) to get the spatial imaging of the fluctuating order in the k-space. We have developed statistical methods of data analysis of scanning μXRD to get new information on the statistical physics of complex heterogeneous systems. Using this novel application of SμXRD we have shown the percolative nature of superconductivity in unconventional high temperature superconductors made of networks of striped nanoscale grains called superstripes. We have shown that the statistical physics of the scale free spatial distribution of the superconducting grains controls the amplification of the critical temperature. This year we have started to shed light on the myelin degradation dynamics relevant in neuron degenerative diseases using SμXRD. We have found a transition from a lognormal distribution to a normal distribution of nanoscale lattice fluctuations in the early stage of demyelination. [1] "Scale-free structural organization of oxygen interstitials in La2CuO4+y M. Fratini, N. Poccia, A. Ricci, G. Campi, M. Burghammer, G. Aeppli & A. Bianconi Nature 466, 841-844 (2010) doi:10.1038/nature09260 http://www.nature.com/nature/journal/v466/n7308/full/466825a.html [2] Evolution and Control of Oxygen Order in a Cuprate Superconductor” N. Poccia, M. Fratini, A. Ricci, G. Campi, L. Barba, A. Vittorini-Orgeas, G. Bianconi, G. Aeppli, A. Bianconi, Nature Materials, 10, 733-736 (2011), DOI: 10.1038/NMAT3088 [3] "Optimum inhomogeneity of local lattice distortions in La2CuO4+y” N. Poccia, A. Ricci, G. Campi, M. Fratini, A. Puri, D. Di Gioacchino, A. Marcelli, M. Reynolds, M. Burghammer, N. L. Saini, G.Aeppli, A.Bianconi Proc. of the Nat. Acad. of Sciences 109, 15685 (2012), URL http://dx.doi.org/10.1073/pnas.1208492109. [4] Multiscale distribution of oxygen puddles in 1/8 doped YBa2Cu3O6.67 A. Ricci, N. Poccia, G. Campi, F. Coneri, A. S.Caporale, D. Innocenti, M. Burghammer, M. von Zimmermann, A. Bianconi Scientific Reports (2013) [5] "Scanning micro-x-ray diffraction unveils the distribution of oxygen chain nanoscale puddles in YBa2Cu3O6.33” G. Campi, A. Ricci, N. Poccia, L. Barba, G. Arrighetti, M. Burghammer, A. S. Caporale, and A. Bianconi, “Phys. Rev. B 87, 014517 (2013), URL http://dx.doi.org/10.1103/physrevb.87.014517. [6] "Changes of statistical structural fluctuations unveils an early degradation stage of PNS myelin Nicola Poccia, Gaetano Campi, Alessandro Ricci, A. S. Caporale, E. Di Cola, Thomas A. Hawkins, Antonio Bianconi Cell Death and Desease NPG 2014 (CDDIS-14-0324). [7] Shape resonances in superconducting gaps and compexity in superstripes: A Bianconi DOI 10.1007/s10948-013-2205-5 (2014) [8] "Superstripes and complexity in high temperature superconductors A. Bianconi, N. Poccia, Journal of Superconductivity and Novel Magnetism 25, 1403-1412 (July 2012) DOI: 10.1007/s10948-012-1521-5 http://link.springer.com/article/10.1007/s10948-012-1670-6#page-1 [9] "Superstripes" A. Bianconi Int. J. Mod. Phys. B 14, 3289-3297 (2000) doi:10.1142/S0217979200003769 [10] “Process of increasing the critical temperature Tc of a Bulk Superconductor by Making Metal Heterostructures at the Atomic Limit'' Antonio Bianconi United State Patent No. :US 6265 019 B1, July 24, 2001.