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Darhmaoui, H.; Jung, J.

doi:10.1103/physrevb.53.14621

Cited by 59 publications

(31 citation statements)

References 37 publications

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“…The theory predicts the contrasting ultrasonic and magnetic resonance relaxation critical behaviour. Similarly here we have shown many points of agreement between the predictions of the ®lamentary nanodomain model (Phillips 1987, 1990, Darhmaoui and Jung 1996 and recent (1999±2001) STM experiments, including contrasting chemical trends. That these successes should be accidental is no more likely than in any other case of successful theories.…”

supporting

confidence: 84%

“…This indeed appears to have been observed, D 0 º D=2 in the STM data on the Bi surface layer (Howard et al 2001).) A similar estimate (3±4 nm) was obtained in critical current density studies on YBCO that identi®ed the crossover where the coherence length equals the nanodomain size (Darhmaoui and Jung 1996).…”

supporting

confidence: 76%

“…Conclusions In HTSCs the basic planar length scale (coherence length) is set by nanodomain diameters (Darhmaoui and Jung 1996), and the presence of glassy planar nanodomains completely alters all the physical properties. The nanodomains, and only the nanodomains , make possible a discrete intermediate phase (the inaptly and ineptly named`non-Fermi liquid') that exhibits high-temperatur e superconductivity .…”

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confidence: 98%

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Nanodomain structure and function of high-temperature superconductors

Phillips¹

2001

Philosophical Magazine B

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The causes of high-temperature superconductivity are still mysterious, although more than 50 000 experiments have studied this subject. The most severe test of any microscopic theory is generally considered to be its ability to predict the results of future experiments. Here we examine recent (1999±2001) studies of Bi2Sr2CaCu2O8 ‡¯®lms by scanning tunnelling microscopy; these have revealed a nanodomain structure on a scale of 3 nm, which is closely correlated with both superconductive gaps and pseudogaps. This structure and these correlations were predicted as part of a discrete ®lamentary model of hightemperature superconductivity in 1990. The nanodomain diameter of 3 nm was identi®ed in experiments on YBa 2 Cu 3 O 7 in 1996. While none of the experiments can directly establish causes, in the predictive theoretical model it was proposed that the underlying forces generating the nanostructure are ferroelastic. It was also predicted that the strong correlations of the superconductive gap and pseudogap electronic structure with nanostructure are the result of dopant selforganization. Here we describe a new method of preparing boride alloys, and we predict that it may produce materials with T c º 150 K or more.

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supporting

confidence: 84%

supporting

confidence: 76%

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confidence: 98%

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Nanodomain structure and function of high-temperature superconductors

Phillips¹

2001

Philosophical Magazine B

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“…These mechanisms can be distinguished by analyzing the temperature dependence of the critical current. 18 Evidence that intragrain j c has a stronger temperature dependence than intergrain j c is provided by MO imaging of flux penetration into YBa 2 Cu 3 O 7Ϫ␦ crystal containing weak links at different temperatures. 19 The substantial decrease of j c with temperature observed in the present work supports intragrain vortex depinning as the main mechanism limiting current density.…”

Section: Discussionmentioning

confidence: 99%

Spatially resolved studies of chemical composition, critical temperature, and critical current density of a YBa2Cu3O7−δ thin film

Gaevski

Bobyl

Shantsev

et al. 1998

Journal of Applied Physics

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Spatially-resolved studies of a YBa2Cu3O 7−δ thin film bridge using electron probe microanalysis (EPMA), low-temperature scanning electron microscopy (LTSEM), and magneto-optical flux visualization (MO) have been carried out. Variations in chemical composition along the bridge were measured by EPMA with 3 µm resolution. Using LTSEM the spatial distributions of the critical temperature, Tc, and of the local transition width, ∆Tc, were determined with 5 µm resolution. Distributions of magnetic flux over the bridge in an applied magnetic field have been measured at 15 and 50 K by magneto-optical technique. The critical current density jc as a function of coordinate along the bridge was extracted from the measured distributions by a new specially developed method. Significant correlations between jc, Tc, ∆Tc and cation composition have been revealed. It is shown that in low magnetic fields deviation from the stoichiometric composition leads to a decrease in both Tc and jc. The profile of jc follows the Tc-profile on large length scales and has an additional fine structure on short scales. The profile of jc along the bridge normalized to its value at any point is almost independent of temperature.

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“…We assume the coefficient b to be proportional to the critical current value, which is in turn dependent on temperature according to the expression: J c (t) ¼ J 0 (1 À t) n , where t is the reduced temperature t ¼ T/T c and n ¼ 1.5 according the Ginsburg-Landau theory. 18 The temperature dependences of other parameters are expressed via the temperature dependences of the London penetration depth and coherence length. The temperature dependence of the London penetration depth is given by: kðTÞ ¼ k 0 = ffiffiffiffiffiffiffiffi ffi 1-t 4 p (see for example Ref.…”

mentioning

confidence: 99%