Method of producing improved microstructure and properties for ceramic superconductors

Patent · Mon Jan 01 00:00:00 EST 1996

OSTI ID:870456

Singh, Jitendra P ^[1]; Guttschow, Rob A ^[2]; Dusek, Joseph T ^[3]; Poeppel, Roger B ^[4]

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1. Naperville, IL
2. Bloomington, IL
3. Lombard, IL
4. Glen Ellyn, IL

A ceramic superconductor is produced by close control of oxygen partial pressure during sintering of the material. The resulting microstructure of YBa.sub.2 Cu.sub.3 O.sub.x indicates that sintering kinetics are enhanced at reduced p(O.sub.2). The density of specimens sintered at 910.degree. C. increased from 79 to 94% theoretical when p(O.sub.2) was decreased from 0.1 to 0.0001 MPa. The increase in density with decrease in p(O.sub.2) derives from enhanced sintering kinetics, due to increased defect concentration and decreased activation energy of the rate-controlling species undergoing diffusion. Sintering at 910.degree. C. resulted in a fine-grain microstructure, with an average grain size of approximately 4 .mu.m. Such a microstructure results in reduced microcracking, strengths as high as 191 MPa and high critical current density capacity.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• DOE Contract Number: W-31109-ENG-38
• Assignee: University of Chicago (Chicago, IL)
• Patent Number(s): US 5525586
• OSTI ID: 870456
• Country of Publication: United States
• Language: English

Related Subjects

method
producing
improved
microstructure
properties
ceramic
superconductors
superconductor
produced
close
control
oxygen
partial
pressure
sintering
material
resulting
yba
cu
indicates
kinetics
enhanced
reduced
density
specimens
sintered
910
degree
increased
79
94
theoretical
decreased
0001
mpa
increase
decrease
derives
due
defect
concentration
activation
energy
rate-controlling
species
undergoing
diffusion
resulted
fine-grain
average
grain
size
approximately
results
microcracking
strengths
191
critical
current
capacity
ceramic superconductor
average grain
oxygen partial
current density
grain size
partial pressure
critical current
activation energy
close control
ceramic superconductors
resulting microstructure
producing improved
ceramic superco
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