Defects in Decomposed Yba2Cu4Ox(124) Superconductor after Rapid Annealing

1990 ◽  
Vol 209 ◽  
Author(s):  
Y. Li ◽  
Y. Gao ◽  
K. L. Merkle ◽  
H. Shi ◽  
U. Balachandran
Keyword(s):  
Flux Pinning ◽  
Annealing Temperature ◽  
High Resolution Electron Microscopy ◽  
Copper Oxides ◽  
Fine Scale ◽  
Superconducting Transition ◽  
Direction Parallel ◽  
Pinning Centers ◽  
Rapid Annealing ◽  
Resolution Electron

ABSTRACTDecomposition of 124 into 123 has been studied after rapid annealing at temperatures from 800°C to 1000°C. It was foundthat the superconducting transition temperature (Tc) depended on the annealing temperature and atmosphere. For decomposedsamples, fine-scale defects with strong strain contrast are observed in the 123 matrix. High-resolution electron microscopy studies show that the defects are parallel to the (001) planes of the 123 matrix. The length of the defects varies andranges from 5 nm to 50 nm in the direction parallel to the (001) planes. The defects have been interpreted to be copper oxides, which could be flux pinning centers in these materials.

Post-annealing induced defects and their influences on Bi2Sr2CaCu2Oy superconducting thin films

1995 ◽  
Vol 10 (8) ◽  
pp. 1872-1877 ◽  
Author(s):  
Xiao Feng Zhang
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Large Angle ◽  
High Resolution Electron Microscopy ◽  
Superconducting Thin Films ◽  
Superconducting Transition ◽  
Secondary Phases ◽  
Post Annealing ◽  
Resolution Electron ◽  
Induced Defects

Defects in Bi2Sr2Can-1CunOy superconducting thin films annealed in an oxygen atmosphere are examined by high-resolution electron microscopy (HREM). In addition to the majority 2212 (n = 2) phase, subsequent slabs of other homologous phases with n values up to n = 10 are found intergrown in the films. Large-angle tilt grain boundaries and various secondary phases such as CuO, Sr-Cu-O oxides are formed in the films. The occurrence of these defects is attributed to an inhomogeneous Sr, Ca, and Cu distribution induced by the post-annealing. Superconducting transition temperature (Tc) is increased by the annealing under suitable conditions.

L12- and L10-like cation-ordered structures in ZrO2–Y2O3 ceramics

2001 ◽  
Vol 16 (6) ◽  
pp. 1806-1813 ◽  
Author(s):  
J. C. Rao ◽  
Y. Zhou ◽  
D. X. Li
Keyword(s):  
Electron Microscopy ◽  
Computer Simulation ◽  
High Resolution ◽  
Annealing Temperature ◽  
High Resolution Electron Microscopy ◽  
Energy Dispersive ◽  
Ordered Structures ◽  
X Ray ◽  
Resolution Electron

Y0.25Zr0.75O2−x and Y0.5Zr0.5O2−y phases, with L12- and L10- like cation-ordered structures, respectively, have been found in ZrO2–Y2O3 ceramics in both the sintered and annealed states. High-resolution electron microscopy, energy-dispersive x-ray spectroscopy and computer simulation have been used to reveal the presence of the phases. The formation of Y0.25Zr0.75O2−x and Y0.5Zr0.5O2−y phases was initiated during the sintering procedure and developed with the increase in annealing temperature and time. Segregation of yttrium, which was prevalent in different regions even within one grain, induced the formation of Y0.25Zr0.75O2−x and Y0.5Zr0.5O2−y phases.

Crystallization of InSb Phase Near the Bonding Interface of Silicon-on-Insulator Structure

2007 ◽  
Vol 131-133 ◽  
pp. 137-142
Author(s):  
Ida E. Tyschenko ◽  
A.G. Cherkov ◽  
M. Voelskow ◽  
V.P. Popov
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Annealing Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
High Resolution Electron Microscopy ◽  
Sio2 Layer ◽  
Silicon On Insulator ◽  
Bonding Interface ◽  
Experimental Results ◽  
Resolution Electron

The behavior of Sb and In atoms embedded into silicon-on-insulator structure (SOI) near the bonding interface was investigated as a function of annealing temperature. Two kinds of the ionimplanted SOI structures were prepared. First kind of the structures contained the buried SiO2 layer implanted with In+ and Sb+ ions near the top Si/SiO2 interface. In second kind, the ion-implanted regions were placed on each side of the bonding interface: Sb+ ions were implanted into Si film; In+ ions were implanted into SiO2 layer. Rutherford backscattering spectrometry (RBS) and crosssectional high-resolution electron microscopy (XTEM) were employed to study the properties of the prepared structures. The formation of InSb nanocrystals was observed within the SiO2 bulk from first kind of the SOI structures as annealing temperature increased to 1100o C. In the case of the double side implanted SOI structures, an increase in annealing temperature to 1100o C was accompanied by the up-hill diffusion of In atoms from the SiO2 bulk toward the bonding interface and by the endotaxial growth of InSb nanocrystals on the top Si/SiO2 interface. It was concluded from the experimental results that Sb atoms were the nucleation centers of InSb phase.

scholarly journals Titanium Nitride as a New Prospective Material for NanoSQUIDs and Superconducting Nanobridge Electronics

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 466
Author(s):  
Michael I. Faley ◽  
Yuchen Liu ◽  
Rafal E. Dunin-Borkowski
Keyword(s):  
Titanium Nitride ◽  
Josephson Junctions ◽  
Quantum Interference ◽  
Landau Theory ◽  
High Resolution Electron Microscopy ◽  
Room Temperature Resistivity ◽  
Superconducting Transition ◽  
Pulsed Dc ◽  
Resolution Electron ◽  
Tin Thin Films

Nanobridge Josephson junctions and nanometer-scale superconducting quantum interference devices (nanoSQUIDs) based on titanium nitride (TiN) thin films are described. The TiN films have a room temperature resistivity of ~15 µΩ·cm, a superconducting transition temperature Tc of up to 5.3 K and a coherence length ξ(4.2 K) of ~105 nm. They were deposited using pulsed DC magnetron sputtering from a stoichiometric TiN target onto Si (100) substrates that were heated to 800 °C. Electron beam lithography and highly selective reactive ion etching were used to fabricate nanoSQUIDs with 20-nm-wide nanobridge Josephson junctions of variable thickness. X-ray and high-resolution electron microscopy studies were performed. Non-hysteretic I(V) characteristics of the nanobridges and nanoSQUIDs, as well as peak-to-peak modulations of up to 17 µV in the V(B) characteristics of the nanoSQUIDs, were measured at 4.2 K. The technology offers prospects for superconducting electronics based on nanobridge Josephson junctions operating within the framework of the Ginzburg–Landau theory at 4.2 K.

(Y1−x)Ba2Cu3O6+δ (δ≤0.2): Consequences of Doping Tetragonal 123-Type to Induce Superconductivity

1989 ◽  
Vol 156 ◽  
Author(s):  
John B. Parise ◽  
Pratibha L. Gai ◽  
M. K. Crawford ◽  
Eugene M. McCarron
Keyword(s):  
Electron Microscopy ◽  
Structural Model ◽  
Complex Mixture ◽  
High Resolution Electron Microscopy ◽  
Nominal Composition ◽  
Superconducting Transition ◽  
Neutron Diffraction Data ◽  
Structural Refinement ◽  
Copper Oxidation ◽  
Resolution Electron

ABSTRACTSubstitution of Ca(II) for Y(III) into tetragonal YBa2Cu3O6 has been achieved and a superconducting transition has been observed for a material of nominal composition (Y0.5Ca0.5) Ba2Cu3O6 (Tc (onset) ˜50K) [1]. Observations using high resolution electron microscopy show samples with x < 0.3 consist of a complex mixture, including (Y, Ca) Ba2Cu3O6+δ, YBa2Cu3O6+δ, and BaCuO2. Further, structural refinement using neutron diffraction data provide evidence of a solid solution limit at x ˜ 0.3. A direct analogy can be drawn between superconducting (Y1−xCax)Ba2Cu3O6 (0.1 < x < 0.3) and superconductors of the type (Y1−xCax)Pb2Sr2Cu3O8 and (La2−xM(II)x)CuO4. Substitution of the Ca(II) for Y(III) effectively increases the formal copper oxidation state. The refined structural model is fully consistent with partially oxidized CuO2 sheets separated by linear O-Cu(I)-O units.

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