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

3 Aug 1987

Volume 51, Issue 5, pp. 293-377

Page 2 of 2 Pages Previous Page | Jump to Page

Orthorhombic‐tetragonal phase transition in high‐temperature superconductor YBa2Cu3O7

M. O. Eatough, D. S. Ginley, B. Morosin, and E. L. Venturini

Appl. Phys. Lett. 51, 367 (1987); http://dx.doi.org/10.1063/1.98443 (2 pages) | Cited 37 times

Full Text: | Download PDF

Show Abstract
We have determined the effect of elevated temperature on the crystal structure and lattice parameters of the single‐phase high‐temperature superconductor YBa2Cu3O7 using high‐temperature x‐ray powder diffractometry. This compound is orthorhombic below about 550 °C (depending on oxygen partial pressure) and transforms to a tetragonal polymorph at higher temperatures. The reversibility of this transition depends on the oxygen partial pressure. An oxygen ‘‘hopping’’ mechanism with possible oxygen loss, which appears consistent with the known structural details, is proposed for the transition.
Show PACS
64.70.K- Solid-solid transitions
61.66.Fn Inorganic compounds

Superconducting thin films based on La2−xSrxCuO4

O. F. de Lima, J. Mattson, C. H. Sowers, and M. B. Brodsky

Appl. Phys. Lett. 51, 369 (1987); http://dx.doi.org/10.1063/1.98444 (2 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
Superconducting films (300–400 nm thick) of La2−xSrxCuO4 have been prepared by a combined evaporation‐reaction method. Amorphous films of the oxide are formed initially on sapphire substrates at deposition temperatures of 25–400 °C. Crystallized films can then be obtained with the desired tetragonal structure and show superconducting resistive transitions, with onsets between 23–28 K and zero resistivities near 4.2 K. A diamagnetic transition consistent with the onset‐resistive transition is seen for different samples and a critical current density of 0.4 A/cm2 is obtained.
Show PACS
74.78.-w Superconducting films and low-dimensional structures
74.70.-b Superconducting materials other than cuprates
68.55.-a Thin film structure and morphology
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Thulium barium copper oxide: A 90‐K superconductor with a potential 1‐MG upper critical field

J. J. Neumeier, Y. Dalichaouch, J. M. Ferreira, R. R. Hake, B. W. Lee, M. B. Maple, M. S. Torikachvili, K. N. Yang, and H. Zhou

Appl. Phys. Lett. 51, 371 (1987); http://dx.doi.org/10.1063/1.98445 (3 pages) | Cited 10 times

Full Text: | Download PDF

Show Abstract
Upper critical magnetic fields Hc2(T) have been measured resistively for the high‐temperature (Tc≳90 K) superconductors TmBa2Cu3O9−δ and YBa2Cu3O9−δ in applied magnetic fields H up to 9 T. If H at the resistive midpoint is defined as Hc2, then the upper critical field slopes (dHc2/dT)Tc at the superconducting transition temperatures Tc are respectively −2.8 and −1.1 T/K. The Tm‐specimen initial slope is apparently the highest yet reported for 90 K superconductors. Extrapolations from this slope, based on standard, three‐dimensional, dirty‐limit Werthamer, Helfand, Hohenberg, and Maki theory, yield (1) zero‐temperature upper critical fields Hc2(T=0)=99–175 T, where the range is determined by the degree of paramagnetic limitation; (2) Hc2(T=77 K)≊36 T, the upper critical field at the boiling point of liquid nitrogen.
Show PACS
74.25.Op Mixed states, critical fields, and surface sheaths
74.70.-b Superconducting materials other than cuprates

Improved magnetic fine‐structure analysis by simultaneous observation of domains and walls

U. Hartmann

Appl. Phys. Lett. 51, 374 (1987); http://dx.doi.org/10.1063/1.98446 (2 pages)

Full Text: | Download PDF

Show Abstract
An optical technique is presented which permits a simultaneous observation of domains and domain boundaries in transparent and opaque magnetic specimens. The Faraday or Kerr contrast combined with Bitter pattern agglomerations yields a maximum information transference for an investigation of magnetic fine structures. Some results obtained for a uniaxial ferrimagnetic film are discussed.
Show PACS
75.60.Ch Domain walls and domain structure
78.20.Ls Magneto-optical effects
75.50.Gg Ferrimagnetics
75.70.Ak Magnetic properties of monolayers and thin films

Dynamic observation of magnetic domains in amorphous ferromagnetic ribbons driven at line frequencies

H. Mase, R. Shimizu, and T. Ikuta

Appl. Phys. Lett. 51, 376 (1987); http://dx.doi.org/10.1063/1.98447 (2 pages)

Full Text: | Download PDF

Show Abstract
The recently developed dynamic observation technique of R. Shimizu and T. Ikuta [Appl. Phys. Lett. 44, 811 (1984)] for scanning electron microscopy, ‘‘line‐sampling stroboscopy,’’ was used for the observation of magnetic domains in an amorphous ferromagnetic ribbon. The image‐processing technique introduced turned out to be very useful, allowing the behavior of domain walls, which is often obscured by topological contrast, to be clearly observed.
Show PACS
75.60.Ch Domain walls and domain structure
07.78.+s Electron, positron, and ion microscopes; electron diffractometers
75.50.Kj Amorphous and quasicrystalline magnetic materials
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close