Evidence of Two-Dimensional Superconductivity in the Single Crystalline Nanohybrid of Organic-Bismuth Cuprate
01 Aug 2006-Journal of Physical Chemistry B (American Chemical Society)-Vol. 110, Iss: 33, pp 16197-16200
TL;DR: X-ray diffraction and X-ray absorption spectroscopic results clearly demonstrate that the single crystalline nature of the pristine bismuth cuprate remains unchanged even after the intercalation of organic complex as well as those of iodine and mercuric iodide.
Abstract: A coordination compound of HgI(2)(pyridine)(2) can be successfully intercalated into a single crystalline Bi(2)Sr(2)CaCu(2)O(y) high-T(c) superconductor through an interlayer complexation reaction between pyridine molecules and bismuth cuprate pre-intercalated with mercuric iodide. X-ray diffraction and X-ray absorption spectroscopic results clearly demonstrate that the single crystalline nature of the pristine bismuth cuprate remains unchanged even after the intercalation of organic complex as well as those of iodine and mercuric iodide. According to the angle-dependent dc magnetization measurements, the intercalation of bulky organic molecules completely blocks superconductive currents along the c-axis, whereas a superconducting transition along the in-plane direction still occurs in the organic intercalate. In the case of the iodine or mercuric iodide intercalates with smaller lattice expansions, an out-of-plane diamagnetic transition is not wholly quenched but significantly depressed by the intercalation, confirming the reduction of interlayer interaction. The present finding can provide straightforward evidence of the two-dimensionality of high temperature superconductivity in the present cuprate-based nanohybrid material.
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TL;DR: In this paper, the applications of layered nanomaterials as green materials are demonstrated along with their structures and properties, and various eco-friendly materials can be hybridized with layered nanoparticles such as layered double hydroxides (LDHs), hydroxy double salts (HDSs) and cationic clays.
Abstract: In this feature article, the applications of layered nanomaterials as green materials are demonstrated along with their structures and properties. Due to the unique 2-dimensional structures and biocompatibility, various eco- and bio-friendly materials can be hybridized with layered nanoparticles such as layered double hydroxides (LDHs), hydroxy double salts (HDSs) and cationic clays. From small molecules such as drugs, herbicides, fertilizers, and food ingredients to large substances like deoxyribonucelotides (DNA), protein, and enzymes, various functional materials can be incorporated into layered nanoparticles via intercalation reactions to produce green materials with versatile applications. The application fields of layered nanomaterials, especially LDHs, are summarized into three categories; biomolecule reservoir, pharmaceutical and other applications.
201 citations
TL;DR: This Progress Report presents recent advances in topochemical reaction strategies as applied to perovskite and perovSkite-related compounds, with emphasis on structural modifications and corresponding variations in properties.
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118 citations
TL;DR: Adopting the nanosheets of layered cobalt oxide as a precursor, the authors were able to prepare the monodisperse CoO nanocrystals with a particle size of approximately 10 nm as well as the heterolayered film composed of Cobalt oxide monolayer and polycation.
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96 citations
TL;DR: The data demonstrate that a new MTX-LDH nanohybrid exhibits a superior efficacy profile and improved distribution compared to MTX alone and has the potential to enhance therapeutic efficacy via inhibition of tumor proliferation and induction of apoptosis.
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55 citations
TL;DR: The 2D group-VA layered nanomaterials have been attracting increasing attention in recent years due to their intriguing physiochemical properties and functional structures for broad and promising applications.
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51 citations
References
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TL;DR: This model explains recent experiments which have questioned the driving mechanism for dissipation in the superconducting phase of the high-temperature oxide superconductors.
Abstract: In layered superconductors with very weak coupling between the layers the concept of a flux-line lattice breaks down when the field is oriented parallel to the superconducting planes. For an arbitrary field orientation we propose that the formation of an Abrikosov lattice is only related to the perpendicular field component. The parallel field component penetrates as if the superconducting planes were completely decoupled. This model explains recent experiments which have questioned the driving mechanism for dissipation in the superconducting phase of the high-temperature oxide superconductors.
392 citations
TL;DR: In oxide superconductors the local suppression of antiferromagnetic correlations in the vicinity of a hole lowers the energy of the system, leading to a quasi two-dimensional bag of weakened spin order that follows the hole in its motion.
Abstract: In oxide superconductors the local suppression of antiferromagnetic correlations in the vicinity of a hole lowers the energy of the system. This quasi two-dimensional bag of weakened spin order follows the hole in its motion. In addition, holes prefer to share a bag, leading to a strong pairing attraction and a high T c superconductivity. There are many experimental consequences of this mechanism for both the superconducting and normal phases.
379 citations
TL;DR: The decrease of {ital T}{sub {ital c}} in isolated YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} layers with increasing sheet resistance is on the same scale of about {h bar}/{ital e}{sup 2} as observed for ordinary superconductors.
Abstract: The effect of coupling between layers of the high-${\mathit{T}}_{\mathit{c}}$ superconductors was studied by varying both the ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathit{x}}$ and ${\mathrm{PrBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathit{x}}$ layer thicknesses in ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathit{x}}$/${\mathrm{PrBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathit{x}}$ superlattices. Superconductivity was found even when the ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathit{x}}$ layers had nominal thicknesses as small as 12 \AA{} (one unit-cell thickness) but coupling between unit-cell layers is needed to achieve a ${\mathit{T}}_{\mathit{c}}$ of 90 K. The decrease of ${\mathit{T}}_{\mathit{c}}$ in isolated ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathit{x}}$ layers with increasing sheet resistance is on the same scale of about \ensuremath{\Elzxh}/${\mathit{e}}^{2}$ as observed for ordinary superconductors.
265 citations
TL;DR: In this paper, two-dimensional neutron-scattering imaging of YBa2Cu3O6.6 was presented, which revealed that the low-frequency magnetic excitations are virtually identical to those of similarly doped La2−xSrxCuO4.
Abstract: An important feature of the high-transition-temperature (high-Tc) copper oxide superconductors is the magnetism that results from the spins associated with the incomplete outer electronic shells (3d9) of the copper ions. Fluctuations of these spins give rise to magnetic excitations of the material, and might mediate the electron pairing that leads to superconductivity. If the mechanism for high-Tc superconductivity is the same for all copper oxide systems, their spin fluctuations should be universal. But so far, theopposite has seemed to be the case: neutron scattering data reveal clear differences between the spin fluctuations for two major classes of high-Tc materials, La2−xSrxCuO4 (1-3) and YBa2Cu3O7−x (4-6), whose respective building blocks are CuO2 layers and bilayers. Here we report two-dimensional neutron-scattering imaging of YBa2Cu3O6.6, which reveals that the low-frequency magnetic excitations are virtually identical to those of similarly doped La2−xSrxCuO4. Thus, the high-temperature (Tc ≲ 92 K) superconductivity of the former materials may be related to spatially coherent low-frequency spin excitations that were previously thought to be unique to the lower-Tc (<40 K) single-layer La2−xSrxCuO4 family.
211 citations
TL;DR: In this paper, a stage-1 iodine-intercalated high-transition-temperature (high-Tc) superconductor, IBi2Sr2CaCu2Oy, is presented.
Abstract: INTERCALATION compounds are formed by inserting guest atomic or molecular species between weakly bound (usually by van der Waals forces) slabs of host materials without changing the inner crystal structure of the individual slabs. The best-known examples of host materials are graphite and the transition metal dichalcogenides1. These compounds can be made with different stage index n, where n denotes the number of slabs between adjacent intercalated layers. Intercalation provides a unique, well controlled approach to changing the physical and electronic properties of host materials over a wide range1. If intercalation can be adopted in the layered high-transition-temperature (high-Tc) superconductors, it could lead to the ability to engineer their properties, with a view to investigating the mechanism responsible for high-Tc superconductivity, improving the superconducting properties of the pristine materials, and developing new high-Tc superconductors and superconducting devices. We report here the successful synthesis and preliminary physical characterization of a stage-1 iodine-intercalated high- Tc superconductor, IBi2Sr2CaCu2Oy.
149 citations