Oxygen arrangement on Hg0.5Tl0.5Ba2CuOx (100) surface studied by high-resolution electron microscopy

Abstract

Oxygen arrangement on Hg0.5Tl0.5Ba2CuOx (100) surface was studied by high-resolution electron microscopy. The {100} planes were found to be stable and to have preferred atomic surface. A surface structure model of Hg0.5Tl0.5Ba2CuOx was proposed and compared to the image calculations, which indicated the surface consists of Ba layers and oxygen atoms on the (Hg, Tl) layers. The present work indicates that the stable {100} planes of Hg-1201-type superconducting oxides would be suitable for the future device application.

Carbon Nanotube and Gold‐Based Materials: A Symbiosis

“…The contrast of the amorphous carbon in the upper region is brighter than that of the lower one and indicates the atomic step edge of the carbon film. The AuNPs grew to 15 nm by coalescence at elevated temperature and the amorphous carbon graphitized by the catalytic effect [91] of the active Au surface at low temperature, when compared to that of ordinary chemical formation of carbon nanocapsules. [92] All the AuNPs are surrounded and isolated by double or triple graphite sheets, which prevent the nanoparticle from growing and act as cluster protection.…”

“…The self-assembled monolayer (SAM) of the thiol-functionalized nanotubes was prepared by dipping an AuA C H T U N G T R E N N U N G (111) wire into the ethanol suspension followed by ultrasonication in absolute ethanol and drying in a high purity nitrogen steam. [41] microwave radiation MWNTs HAuCl 4 ethylene glycol/microwave radiation 3-10 [45] non-covalent functionalization method MWNTs AuCl 3 (gold nanoclusters) ultrasonication in toluene 1-3 [55] polymer-wrapping and layer-by-layer technique MWNTs silica-coated AuNPs sonication 2-6 [57] non-covalent self assembly MWNTs AuNPs sonication 8 [60] layer-by-layer approach [b] MWNTs gold nanorods sonication 30 [62] non-covalent supramolecular approach MWNTs HAuCl 4 ·3 H 2 O NaBH 4 /stirring in H 2 O 5 [65] electrostatic adsorption CN x MWNTs [c] gold colloids sonication 10 [69] selective attachment MWNTs HAuCl 4 citric acid/stirring 10 [37] electro-chemical reduction MWNTs HAuCl 4 ·3 H 2 O NaBH 4 /stirring in H 2 O polydisperse [73] high-density assembly MWNTs HAuCl 4 sodium citrate and NaBH 4 /stirring in H 2 O 2-4 [74] solution-phase dispersion SWNTs KAuCl 4 none 3 [75] sonication assisted technique MWNTs HAuCl 4 NaOH/sonication - [77] sonication SWNTs/ MWNTs AuNPs stirred in CH 2 Cl 2 and sonication 2-5 [80] chemical vapor deposition MWNTs pure Au target e-beam evaporator 5 [84] MWNTs HAuCl 4 ·4 H 2 O NaBH 4 /stirring in H 2 O at room temperature 2-7 [85] wet chemical self-assembling SWNTs Au wire ultrasonication in absolute ethanol 20-60 [88] one-dimensional self organized technique carbon film AuNPs a-terpineol in toluene/annealed at 200-400 8C 5 [91] [a] Inside the nanotubes. The resulting structures have been also confirmed by AFM in Figure 8, where the substrate showed a series of atomically flat triangle terraces, characteristic of AuA C H T U N G T R E N N U N G (111) facets before the adsorption of nanotubes, where needle-like protrusions are clearly seen on the gold surface after adsorption.…”

High-resolution electron microscopy and electron diffraction of perovskite-type superconducting copper oxides

“…On the other hand, the surface structures of the fracture nearly perpendicular to the c-axis show complex structures formed by rearrangement of atoms near the edge. However, Hg-based copper oxides showed stable surface [123,124]. The characteristics of various surface structures should be taken into consideration, when the properties are sensitive to surface structures.…”

Three-dimensional imaging of YB56 by high-resolution electron microscopyElectronic supplementary information (ESI) available: Table S1: three-dimensional amplitudes and symmetrized phases of YB56 in Fourier transform derived by crystallographic image processing of HREM images, and amplitudes obtained from electron diffraction patterns. See http://www.rsc.org/suppdata/cc/b1/b107864j/

“…2,3,6 High-resolution electron microscopy (HREM) is a powerful method for direct observation of the atomic structure of advanced materials. [7][8][9] In previous works, 10,11 the Y-holes in YB 56 were directly detected in the boron clusters by HREM, and the 'local' structure model was proposed for yttrium atom arrangements. In addition, a residual index (R HREM = I obs 2 I calc /I obs ) was used for image analysis to determine the crystal thickness and defocus value of the observed images, and differential images showed the atomic disordering of the boron atoms around the Y-holes.…”