Stripe structure and Non-Homogeneity of the CuO₂Plane by Joint EXAFS and Diffraction

Abstract

Local structure of the Cu02 plane in Bi2Sr2CaCu208+8 (Bi2212) superconductor has been solved by joint Cu K-edge extended X-ray absorption fine structure (EXAFS) and anomalous X-ray diffraction. The Cu-0 pair distribution function (PDF) has been measured by EXAFS and diffraction. The displacement of the Cu ions along the c-axis shows largest amplitude and anharmonic character. The results show flat stripes of the Cu02 lattice of width L = 15 =& 0.5 A that are separated by stripes of bent Cu02 plane.The modulation of the Cu02 plane measured by EXAFS and anomalous diffraction has been discussed.

Controlling mesoscopic phase separation near electronic topological transitions via quenched disorder in ternary diborides

“…It has also been called a Feshbach shape resonance [23][24][25]. The high superconducting critical temperature in cuprates [28][29][30][31][32][33] and diborides [33][34][35] has been assigned to these resonances.…”

The effect of Ca and Th substitution on the crystal-field spectrum of the high-Tcsuperconductor HoBa2Cu3Ox

“…It was shown theoretically that the presence of holes makes layered antiferromagnets unstable against phase separation into holerich and hole-poor regions at intermediate length scales [1][2][3][4][5][6]. At the same time, there is growing experimental evidence for mesoscopic striped phases and their effect on the electronic properties in perovskite materials [7][8][9][10][11][12][13][14][15][16]. It is therefore of crucial interest to obtain direct experimental information on the charge distribution within the superconducting CuO 2 planes of high-T c cuprates.…”

Crystal-field spectrum in RBa2Cu3Ox(R = Er, Ho) high-Tcsuperconductors: evidence for charge order in CuO2planes

“…(i) Our model emphasizes the ordered charge arrangement in a unit cell. The width of charge tapes W ≈ a/2 (a is the in-plane lattice parameter) is by order of magnitude less than the width of stripes which is about 15 Å [20,22,[27][28][29]. In terms of our model any attempt to extend stripe width up to a few lattice constants would result in strong contradiction with the observed behaviour of the CEF parameters.…”

“…It has been theoretically shown that dilute holes in a layered antiferromagnet can be unstable against phase separation into hole-rich and hole-poor regions at intermediate length scales [2][3][4][5][6][7]. At the same time there is growing experimental evidence for mesoscopic striped phases and their effect on the electronic properties in perovskite materials [20][21][22][23][24][25][26][27][28][29]. It is therefore of crucial interest to obtain direct experimental information on charge distribution within the superconducting CuO 2 planes of high-T c cuprates.…”

“…The formation of the periodic array of charged tapes provides evidence for a charge order occurring in the CuO 2 planes due to doping. However, this order cannot directly be identified with charge stripes widely discussed from both theoretical [2][3][4][5][6][7] and experimental sides [20][21][22][23][24][25][26][27][28][29].…”