skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Grain boundary degradation of YBCO superconductors sintered in CO{sub 2}-containing atmospheres

Abstract

The transport critical current density (J{sub c}) of YBCO superconductors decreased with increasing CO{sub 2} partial pressure in the sintering atmosphere and ultimately reached zero, even though magnetization measurements showed that the bulk of the samples with zero J{sub c} remained superconducting. The microstructure and composition of the samples was investigated by high resolution transmission electron microscopy and secondary-ion mass spectroscopy (SIMS). Microbeam SIMS indicated carbon segregation at grain boundaries (GBs). Approximately 10% of the GBs were coated with a thin layer of a second phase, deduced to be BaCuO{sub 2} and BaCu{sub 2}O{sub 2}. Near some grain boundaries, the structure was tetragonal within several tens of nm of the boundaries. The degradation of J{sub c} is discussed in terms of the partial pressure of CO{sub 2} and the processing temperatures. Detailed examination of GB microstructures is given in this paper.

Authors:
; ;  [1];  [2]; ; ;  [3]
  1. Argonne National Lab., IL (United States)
  2. New Mexico Inst. of Mining and Metallurgy, Socorro, NM (United States). Dept. of Materials and Metallurgical Engineering
  3. San Jose State Univ., CA (United States). Dept. of Materials Engineering
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
OSTI Identifier:
10194903
Report Number(s):
ANL/ET/CP-78725; CONF-931142-4
ON: DE94003206; CNN: Contract DMR88-09854; TRN: 94:000788
DOE Contract Number:  
W-31109-ENG-38
Resource Type:
Technical Report
Resource Relation:
Conference: 1. meeting of the Pacific Rim ceramic societies,Honolulu, HI (United States),7-10 Nov 1993; Other Information: PBD: Nov 1993
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; YTTRIUM OXIDES; CRITICAL CURRENT; MICROSTRUCTURE; BARIUM OXIDES; COPPER OXIDES; HIGH-TC SUPERCONDUCTORS; CURRENT DENSITY; PRESSURE DEPENDENCE; CARBON DIOXIDE; SUPERCONDUCTIVITY; TRANSMISSION ELECTRON MICROSCOPY; SEGREGATION; GRAIN BOUNDARIES; EXPERIMENTAL DATA; SINTERING; 360207; 360202

Citation Formats

Balachandran, U, Merkle, K L, Mundy, J N, Gao, Y, Zhang, C, Xu, D, and Selvaduray, G. Grain boundary degradation of YBCO superconductors sintered in CO{sub 2}-containing atmospheres. United States: N. p., 1993. Web. doi:10.2172/10194903.
Balachandran, U, Merkle, K L, Mundy, J N, Gao, Y, Zhang, C, Xu, D, & Selvaduray, G. Grain boundary degradation of YBCO superconductors sintered in CO{sub 2}-containing atmospheres. United States. https://doi.org/10.2172/10194903
Balachandran, U, Merkle, K L, Mundy, J N, Gao, Y, Zhang, C, Xu, D, and Selvaduray, G. 1993. "Grain boundary degradation of YBCO superconductors sintered in CO{sub 2}-containing atmospheres". United States. https://doi.org/10.2172/10194903. https://www.osti.gov/servlets/purl/10194903.
@article{osti_10194903,
title = {Grain boundary degradation of YBCO superconductors sintered in CO{sub 2}-containing atmospheres},
author = {Balachandran, U and Merkle, K L and Mundy, J N and Gao, Y and Zhang, C and Xu, D and Selvaduray, G},
abstractNote = {The transport critical current density (J{sub c}) of YBCO superconductors decreased with increasing CO{sub 2} partial pressure in the sintering atmosphere and ultimately reached zero, even though magnetization measurements showed that the bulk of the samples with zero J{sub c} remained superconducting. The microstructure and composition of the samples was investigated by high resolution transmission electron microscopy and secondary-ion mass spectroscopy (SIMS). Microbeam SIMS indicated carbon segregation at grain boundaries (GBs). Approximately 10% of the GBs were coated with a thin layer of a second phase, deduced to be BaCuO{sub 2} and BaCu{sub 2}O{sub 2}. Near some grain boundaries, the structure was tetragonal within several tens of nm of the boundaries. The degradation of J{sub c} is discussed in terms of the partial pressure of CO{sub 2} and the processing temperatures. Detailed examination of GB microstructures is given in this paper.},
doi = {10.2172/10194903},
url = {https://www.osti.gov/biblio/10194903}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Nov 01 00:00:00 EST 1993},
month = {Mon Nov 01 00:00:00 EST 1993}
}