& SURFACE TECHNOLOGY ALERT
JANUARY 4, 1999
John Wiley & Sons, Inc., New York.
'Advanced Coatings & Surface
Technology Alert' reports and puts
perspective significant developments in coatings and surface modification
across a broad range of industry lines. Emphasis is on advanced coatings
techniques - lasers, vapor deposition, and vacuum techniques, offering
interdisciplinary analyses of those that have true commercial potential. This
service includes patent coverage.
PLD FOR SUPERIOR THIN
Engineers and scientists are looking at novel materials for high
temperature superconducting (HTSC) thin films for use in passive microwave
devices, such as microwave filters for mobile and satellite communications.
One promising candidate being used now in satellite systems is Yba2Cu3O7,
commonly referred to as YBCO. The challenge is growing a high-quality film
over a large area, and making it affordable. There are several deposition
techniques including sputtering, thermal coevaporation, MOCVD and PLD, and
each has its advantages and disadvantages.
However, one particular deposition process appears to be ahead of the
pack. Physicists in Germany have developed an advanced pulsed laser
deposition (PLD) process for growing double-sided Ag-doped YBCO films for
large area application. What makes their PLD technique innovative is the
simple deposition arrangement, high deposition rate, and the ability to
deposit multielement compounds as simply as stoichiometric and epitaxial thin
Michael Lorenz, a physicist at Leipzig University (Germany), and his
colleagues developed the advanced PLD process. They have also analyzed their
PLD Ag-doped YBCO films using Raman spectroscopy, SEM, SNMS depth profiling,
and TEM cross section. Results show that the microwave handling power of his
PLD films are comparable to the same films prepared by other techniques and
on other substrates
The process is patent-pending and researchers are open to any
scientific cooperation, however, they are restricted in their ability to work
with foreign partners in the field of microwave application of HTSC thin
Details: Dr. Michael Lorenz, Leipzig University, Linnestrasse 5,
D-04103 Leipzig, Germany. Phone: +49-341-97-32661. Fax: +49-341-97-32698.
Copyright 1999, John Wiley & Sons,
Inc., New York, NY 10158
Leipziger Volkszeitung vom 09. März 1999