実験報告書様式（一般利用課題・成果公開利用）

MLF Experimental Report
課題番号 Project No.

提出日 Date of Report
20/4/2013
装置責任者 Name of responsible person

2012B0225

Kazuya Aizawa

実験課題名 T itle of experiment

Stefanus Harjo

Neutron diffraction study of sintering reaction processes forsuperconducting materials

装置名 Name of Instrument/（BL No.）
TAKUMI/(BL 19)

実験責任者名 Name of principal investigator

実施日 Date of Experiment

Yoshinori Tsuchiya

21/12/2012-23/12/2012

所属 Affiliation

1/2/2013-4/2/2013

National Institute for Materials Science
試料、実験方法、利用の結果得られた主なデータ、考察、結論等を、記述して下さい。（適宜、図表添付のこと）
Please report your samples, experimental method and results, discussion and conclusions. Please add figures andtables for better explanation.
1. 試料 Name of sample(s) and chemical formula, or compositions including physical form.
Samples:
Ag-sheathed (Bi,Pb) 2 Sr 2 Ca2 Cu3 Ox monofilament tape (Bi,Pb-2223/Ag)
Ag-sheathed (Bi,Pb) 2 Sr 2 CaCu2 Ox monofilament tape (Bi,Pb-2212/Ag)
Physical form:
Tape (4 x 40 x 0.3 mm 3)

2. 実験方法及び結果 （実験がうまくいかなかった場合、その理由を記述してください。）
Experimental method and results. If you failed to conduct experiment as planned, please describe reasons.
1. Neutron diffraction measurements at room temperature for heat -treated samples
Heat-treated BSCCO/Ag tapes have been prepared in advance under various conditions of gas atmosphere.
The gas atmosphere of heat -treatments was mixture of nitrogen and oxygen.
superconducting layer of the sample was a Bi2212 phase.
pressure was controlled in 1 to 3 atm.

A starting state of aConcentration of the oxygen was set to 2 to 25% andAn annealing temperature was set to 830 C and an annealing time was 12hours. The neutron diffraction measurements were performed at room temperature. The annealed samples
were set perpendicularly and the tape surface and applied to 45 degrees to an incident beam.

An exposure time

was about 2 hours for one sample.
Figure 1 shows the diffraction patterns of the heat-treated samples that annealed in 1 atm for various
oxygen concentrations. In the heat-treatment condition of 1 atm and 12 hours annealing, it was found that aBi2223 phase was appeared at the oxygen concentration of 2 to 20 % as shown in fig. 1 by open circles.
Especially, diffraction peaks of the Bi2223 phase were appeared strongly in the sample annealed in oxygen12. 実験方法及び結果（つづき） Experimental method and results (continued)
concentration of 5 and 10%. The diffraction peaks of the Bi2212 phase were relatively decreased for theseannealing conditions.
2. In-situ neutron diffraction measurements during heat-treatment for various oxygen concentration and gas
pressure
In order to observe a phase transition process in the heat-treatment of an actual superconducting wire, weperformed an in-situ neutron diffraction measurement installing a gold-image furnace on a sample stage of theTAKUMI diffractometer.

Starting sample was an untreated Bi2212/Ag tape and the sample was put into aplatinum cell of the furnace. The annealing temperature was set to 830 C.
made in different heat-treating atmosphere.
measurement.

In this study, three attempts were

The heat -treatment process was about 6 hours for one

A diffraction data was corrected as an event data in the whole measurement run, and the data

was treated by a time-sharing process.
Figure 2 shows time-sharing neutron diffraction spectra of BSCCO/Ag tape during the annealing processof 830 C. The atmosphere was 1 atm and 5% of oxygen concentration. The spectra were integrated in every
15 minutes. As shown in fig. 2, peak intensities of the Bi2223 phase increased while that of the Bi2212 phasedecreased with the annealing time.

Namely, the phase transition behavior of Bi-superconducting phase wasobserved through a sheath material for an actual wire.

Fig.1 Neutron diffraction patterns ofFig.2 Change of neutron diffraction patterns during

heat-treated BSCCO/Ag tapes underheat-treatment process of BSCCO/Ag tape. Filled circles

various oxygen concentrations at 830C.

indicate Bi2212 phase while open circles show Bi2223.

Filled circles indicate Bi2212 phase while
open circles show Bi2223.

2