Pulsed microwave processing of high- Tc superconducting films

Conference · Wed Jan 01 04:00:00 EST 1992

OSTI ID:5161526

James, R B; McCarty, K F; Friedmann, T A; Stulen, R H; Ginley, D S ^[1]; Alvarez, R A ^[2]; Stamper, A K; Bao, X J; Schlesinger, T E ^[3]

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1. Sandia National Labs., Livermore, CA (United States)
2. Lawrence Livermore National Lab., CA (United States)
3. Carnegie-Mellon Univ., Pittsburgh, PA (United States). Dept. of Electrical and Computer Engineering

We have used 2.0-{mu}sec microwave pulses at a frequency of 2.856 GHz to rapidly heat thin amorphous yttrium-barium-copper-oxide (YBCO) films deposited onto silicon substrates. The samples were irradiated inside a WR-284 waveguide by single-pass TE{sub 10} pulses in a traveling wave geometry. X-ray diffractometry studies show that an amorphous-to-crystalline phase transition occurs for incident pulse powers exceeding about 6 MW, in which case the amorphous YBCO layer is converted to Y{sub 2}BaCuO{sub 5}. Microscopy of the irradiated film reveals that the phase transition is brought about by melting of the YBCO precursor film and crystallization of the molten layer upon solidification. Time-resolved in situ experiments of the microwave reflectivity (R) and transmissivity (T) show that there is an abrupt change in R for microwave pulse powers exceeding the melt threshold, so that measurements of R and T can be used to monitor the onset of surface melting.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5161526
• Report Number(s): SAND-92-1183C; CONF-920402--22; ON: DE92014950
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360605 -- Materials-- Radiation Effects
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
DIFFRACTION
ELECTROMAGNETIC RADIATION
FILMS
HEATING
HIGH-TC SUPERCONDUCTORS
MICROWAVE RADIATION
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADIATION EFFECTS
RADIATION HEATING
RADIATIONS
REFLECTIVITY
SCATTERING
SUPERCONDUCTING FILMS
SUPERCONDUCTORS
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
YTTRIUM COMPOUNDS
YTTRIUM OXIDES