NIST High Temp. Superconducting Materials (HTS) Database

NIST High Temp. Superconducting Materials (HTS) Database:

NIST Standard Reference Database 62

Last Update to Data Content: 1996

DOI: https://doi.org/10.18434/T4KP8J

Bibliographic Information

Title: The Oxygen Conductivity and Chemical Diffusion in YBa₂Cu₃O_6+x
Author(s): M.V. Patrakeev, I.A. Leonidov, V.L. Kozhevnikov, V.I. Tsidilkovskii, and A.K. Demin
Publication: Physica C Volume: 210 Issue: Not Available Year: 1993 Page(s): 213-220
Editor(s): Not Available
Publisher: Elsevier Science Publishers B.V.
Language: English
Notes: Not Available
Keywords: Material Specification, Diffusion Coefficient

Materials and Properties

Material Specification for Y:123; [Y-Ba-Cu-O] Process: Solid State Reaction
Notes: "The specimens of YBa₂Cu₃O_6+x were synthesized using reagent grade Y₂O₃ (99.999%), CuO (99.995%) and BaCO₃ (99.997%) via solid state reaction... The desirable amounts of the starting reagents were milled together using an ultramill made of boron nitride (Retch). A part of the mixture was pressed and used as a substrate for the major batch, to prevent its unintended contamination with the material of a crucible. The slightly pressed pellets of the materials under synthesis were calcined at 910 °C in air. The phase purity of the samples was determined using a diffractometer Stadi-P (Stoe). The pellets were crushed, repressed, and fired several times before a single phase material was obtained. The synthesized powder... was used for hot-pressing of ceramic disks with thickness of 1.4-1.5 mm. Then the samples were polished down to 0.8-1.2 mm thickness using corundum and diamond powders adding absolute ethanol, and rinsed out in the ethanol... After treatment in oxygen at 450 °C for 100 h (measurements were made)."
Formula: YBa₂Cu₃O_x
Informal Name: Y:123
Chemical Family: Y-Ba-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:

Diffusion Coefficient for Y:123; [Y-Ba-Cu-O]

x of O_x (formula units)	Temperature (K)	Diffusion Coefficient (log10(cm²/s))
6.55	1028	-4.2
6.55	1005	-4.5
6.55	954	-5.0
6.55	924	-5.3
6.45	1077	-4.5
6.45	1025	-5.0
6.45	1003	-5.2
6.45	955	-5.7
6.35	1119	-4.8
6.35	1078	-5.1
6.35	1026	-5.6
6.35	1004	-5.9
6.35	979	-6.1

Measurement Method: Steady state O₂ flow
"The steady oxygen flow through the mixed ionic-electronic conductor... was measured. The plate of YBa₂Cu₃O_6+x separated the volume with higher partial pressure of oxygen... from the volume with lower partial pressure of oxygen... The measurements were carried out using an electochemical cell... which was tube-shaped and made of stabilized zirconia solid electrolyte. The platinum electrodes were deposited on the inner and outer surfaces of the tube. These electrodes formed an electrochemical oxygen pump and an oxygen sensor. A thin layer of high-temperature glass was deposited on the ring edge of the cell and then the specimen under study was attached. The whole assemblage was covered with an external quartz ampule and placed into a furnace. The values of ionic conductivity of oxygen were determined in conditions of steady flow of oxygen through a specimen. The steady state in the cell was achieved in 10-70 h dependent on temperature and the step of temperature change... the value (of the diffusion coefficient) depends substantially on ( x of O_x ). Because of this, it seems reasonable to give, here, the values of (the diffusion coefficient) calculated according to the Nernst-Eintein relation..."

Cautions: Evaluated Data
Digitized data were obtained from Figure 6 of the paper.