APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

10 Sep 1990

Volume 57, Issue 11, pp. 1075-1169

Page 2 of 2 Pages Previous Page | Jump to Page

Laser writing of superconducting patterns on YBa2Cu3Ox films

R. C. Dye, R. E. Muenchausen, N. S. Nogar, A. Mukherjee, and S. R. J. Brueck

Appl. Phys. Lett. 57, 1149 (1990); http://dx.doi.org/10.1063/1.104222 (3 pages) | Cited 13 times

Full Text: | Download PDF

Show Abstract
A novel process for the direct laser writing of thin‐film high Tc patterns is demonstrated. The process consists of deposition of a high quality film (308 nm laser ablation from a YBa2Cu3Ox target with a 750 °C substrate temperature and a 150 mTorr O2 ambient), annealing in an inert atmosphere (Ar at 400 °C for 5–20 min) to reduce the oxygen content and depress or eliminate the superconducting transition temperature, and direct‐write laser heating (1.06 μm at ≊0.5 kW/cm2 for ≊5 min) in an oxygen atmosphere at ≊590 Torr to selectively regenerate the high Tc material. rf eddy current and four‐point resistivity probe results confirm this process for both SrTiO3 and LaAlO3 substrates. Scanning electron micrographs indicate that this is a very mild processing sequence with no observable changes in film morphology.
Show PACS
74.78.-w Superconducting films and low-dimensional structures
74.70.-b Superconducting materials other than cuprates
74.25.Sv Critical currents
74.62.Bf Effects of material synthesis, crystal structure, and chemical composition
74.20.Mn Nonconventional mechanisms
74.20.Rp Pairing symmetries (other than s-wave)

Anisotropic proximity coupling in small YBa2Cu3O7‐normal‐Pb junctions

Mark Lee, D. Lew, C. B. Eom, T. H. Geballe, and M. R. Beasley

Appl. Phys. Lett. 57, 1152 (1990); http://dx.doi.org/10.1063/1.103517 (3 pages) | Cited 36 times

Full Text: | Download PDF

Show Abstract
We report results of current‐voltage measurements made on small‐area YBa2Cu3O7‐N‐Pb thin‐film junctions (N=Au, Ag) where the orientation of the Cu‐O plane has been varied from (001) to (103) to (100) to study the effects of anisotropy. For (001) and (103) oriented junctions there is no well defined supercurrent despite very low contact resistances. By contrast, (100) junctions do display a well defined supercurrent. We compare these results to recent Josephson work and discuss implications for tunnellng and device work.
Show PACS
74.50.+r Tunneling phenomena; Josephson effects
74.78.-w Superconducting films and low-dimensional structures
74.70.-b Superconducting materials other than cuprates

Scaling behavior of YBa2Cu3O7−δ thin‐film weak links

S. E. Russek, D. K. Lathrop, B. H. Moeckly, R. A. Buhrman, D. H. Shin, and J. Silcox

Appl. Phys. Lett. 57, 1155 (1990); http://dx.doi.org/10.1063/1.104223 (3 pages) | Cited 76 times

Full Text: | Download PDF

Show Abstract
The superconductive weak link properties of microbridges formed in c‐axis normal YBa2Cu3O7−δ polycrystalline thin films containing a variable amount of large angle tilt boundaries have been studied. In the low critical current density limit these weak links have current‐voltage (I‐V) characteristics that are accurately modeled by the resistively shunted junction model. The I‐V’s are found to accurately follow a simple scaling law with the product of the critical current and weak link resistance Rn varying linearly with the weak link conductance.
Show PACS
74.78.-w Superconducting films and low-dimensional structures
74.50.+r Tunneling phenomena; Josephson effects
74.25.Sv Critical currents
74.62.Bf Effects of material synthesis, crystal structure, and chemical composition

Microstructure of Cu‐ and Y‐rich YBa2Cu3O7−x thin films: Identification of the CuYO2 phase

A. F. Marshall, V. Matijasevic, P. Rosenthal, K. Shinohara, R. H. Hammond, and M. R. Beasley

Appl. Phys. Lett. 57, 1158 (1990); http://dx.doi.org/10.1063/1.104224 (3 pages) | Cited 23 times

Full Text: | Download PDF

Show Abstract
The CuYO2 delafossite‐type structure has been identified as a second phase in thin films of Cu‐ and Y‐rich YBa2Cu3O7−x (123) made by electron beam co‐evaporation at conditions of low oxygen pressure; this phase occurs as extremely small, densely distributed, highly oriented precipitates within the 123 matrix. The smallest (sub‐100 Å) [00.1] oriented precipitates of this hexagonal phase are strained to give a better lattice match to the surrounding 123 structure. The results suggest that, for thin film deposition conditions of sufficiently low temperature and pressure, there may be a tie line between YBa2Cu3O7−x and CuYO2 in the equilibrium phase diagram. The size and distribution of the precipitates is such as would be expected to influence structurally sensitive superconducting transport properties.
Show PACS
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
68.55.Nq Composition and phase identification
07.79.Cz Scanning tunneling microscopes
61.05.-a Techniques for structure determination
74.78.-w Superconducting films and low-dimensional structures

High critical currents in strained epitaxial YBa2Cu3O7−δ on Si

D. K. Fork, D. B. Fenner, R. W. Barton, Julia M. Phillips, G. A. N. Connell, J. B. Boyce, and T. H. Geballe

Appl. Phys. Lett. 57, 1161 (1990); http://dx.doi.org/10.1063/1.104225 (3 pages) | Cited 153 times

Full Text: | Download PDF

Show Abstract
Epitaxial YBa2Cu3O7−δ (YBCO) films were grown on Si (100) using an intermediate buffer layer of yttria‐stabilized zirconia. Both layers are grown via an entirely in situ process by pulsed laser deposition. All films consist of c‐axis oriented grains as measured by x‐ray diffraction. Strain results from the large difference in thermal expansion coefficients between Si and YBCO. Thin (<500 Å) YBCO films are unrelaxed and under tensile strain with a distorted unit cell. Rutherford backscattering spectroscopy indicates a high degree of crystalline perfection with a channeling minimum yield for Ba as low as 12%. The normal‐state resistivity is 280 μΩ cm at 300 K; the critical temperature Tc (R=0) is 86–88 K with a transition width (ΔTc) of 1 K. Critical current densities of 2×107 A/cm2 at 4.2 K and 2.2×106 A/cm2 at 77 K have been achieved.
Show PACS
74.78.-w Superconducting films and low-dimensional structures
74.25.Sv Critical currents
81.15.Kk Vapor phase epitaxy; growth from vapor phase
68.60.Dv Thermal stability; thermal effects

High critical current densities in YBa2Cu3O7−x films on polycrystalline zirconia

David P. Norton, Douglas H. Lowndes, J. D. Budai, D. K. Christen, E. C. Jones, K. W. Lay, and J. E. Tkaczyk

Appl. Phys. Lett. 57, 1164 (1990); http://dx.doi.org/10.1063/1.104226 (3 pages) | Cited 27 times

Full Text: | Download PDF

Show Abstract
We report the growth on polycrystalline yttria‐stabilized zirconia substrates of YBa2Cu3O7−x films with Jc (77 K)=11 000 A/cm2 and Jc (4.2 K)=122 000 A/cm2 by pulsed laser ablation. These Jc values are among the highest reported for YBa2Cu3O7−x on any polycrystalline substrate and approach the intrinsic upper limit for films with large‐angle grain boundaries, as indicated by recent bicrystal experiments. We find that the substrate temperature during film growth is most important in obtaining high Jc polycrystalline films. Although the magnetic field dependence of Jc indicates the presence of weak links, the behavior of Jc (4.2 K, H) suggests that a percolative path consisting of low‐angle grain boundaries exists in the films, resulting in Jc (4.2 K, 60 kOe)=4100 A/cm2.
Show PACS
74.25.Sv Critical currents
74.78.-w Superconducting films and low-dimensional structures
74.70.-b Superconducting materials other than cuprates

Role of copper in electromigration lifetimes of aluminum alloy conductors

J. R. Lloyd

Appl. Phys. Lett. 57, 1167 (1990); http://dx.doi.org/10.1063/1.103518 (2 pages) | Cited 13 times

Full Text: | Download PDF

Show Abstract
Recent experimental results have indicated that the traditionally conceived role of copper in Al/Cu alloys in electromigration resistance may not be correct. A simple model is proposed based on Al/Cu intermetallic precipitates acting as local diffusion barriers limiting vacancy availability.
Show PACS
82.45.-h Electrochemistry and electrophoresis
66.30.Fq Self-diffusion in metals, semimetals, and alloys
66.30.J- Diffusion of impurities
FREE

Erratum: Josephson weak links in thin films of YBa2Cu3O7−x induced by electrical pulses [Appl. Phys. Lett. 56, 2240 (1990)]

D. Robbes, A. H. Miklich, J. J. Kingston, Ph. Lerch, F. C. Wellstood, and John Clarke

Appl. Phys. Lett. 57, 1169 (1990); http://dx.doi.org/10.1063/1.104088 (1 page)

Full Text: | Download PDF

Abstract Unavailable
Show PACS
85.25.Cp Josephson devices
74.70.-b Superconducting materials other than cuprates
74.78.-w Superconducting films and low-dimensional structures
99.10.Cd Errata
FREE

Erratum: Particulates reduction in laser‐ablated YBa2Cu3O7−δ thin films by laser‐induced plume heating [Appl. Phys. Lett. 56, 2144 (1990)]

G. Koren, R. J. Baseman, A. Gupta, M. I. Lutwyche, and R. B. Laibowitz

Appl. Phys. Lett. 57, 1169 (1990); http://dx.doi.org/10.1063/1.104289 (1 page)

Full Text: | Download PDF

Abstract Unavailable
Show PACS
74.78.-w Superconducting films and low-dimensional structures
74.70.-b Superconducting materials other than cuprates
79.20.Ds Laser-beam impact phenomena
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
99.10.Cd Errata
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close