実験報告書様式（一般利用課題・成果公開利用）

MLF Experimental Report

提出日 Date of Report

課題番号 Project No.

装置責任者 Name of responsible person

2015A0071

Kenichi Oikawa

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）

Influence of neutron radiation on Ge-S (Se) films and dual film

NOBORU (BL10)

structures containing Ge-S (Se) /Ag films

実施日 Date of Experiment

実験責任者名 Name of principal investigator

March 15, 2016

Yoshifumi Sakaguchi
所属 Affiliation
CROSS
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.
GexS100-x film, GexSe100-x film, GexS100-x/ Ag film, GexSe100-x/ Ag film (x=20, 33, 40)

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.

We prepared 12 sample packages which are made of aluminum
coated polythene sheet (110mm x 110mm) and in which 12 setsof different films are contained. Fig.1 shows the photograph of
the inside of the sample package. One sample package was set
on the beam path in order that all of the films in the package wereexposed to the neutron beam with 100mm x 100mm beam size.
Also, one other sample package was set on out of the neutron
beam path as a control. The sample packages were exposed toFig.1

the neutron beam with two different filter conditions(without filter and with bismuth filter) and for threesample package

different times (10 min, 1 hour, and more than 8 hours)
as summarized in Table 1. One day beam time wasneutrons

used for the neutron beam irradiation. After cooling
down of the irradiated samples, the samples wereshipped to Boise State University (U.S.A.) and theeffect of the neutron irradiation was investigated by
Raman spectrometer.
Fig.2
1

2. 実験方法及び結果（つづき） Experimental method and results (continued)
The Raman studies revealed that the studied
samples have the specific features, characteristic
for the particular Ge-S(Se) compositions. Example isNo filter

10min

1 hour

9.5 hours

Bi filter

10min

1 hour10 hoursTable 1

the Raman curve for the Ge30Se70 composition. It

represents the corner-sharing (CS), edge-sharing (ES) and Se chains (Se-Se) structural units building thiscomposition after the films have been irradiated for 1 hour and 8 hours – Fig. 3. It is obvious that there aresome, even though small changes in the films structure after different dose of irradiation. To make it better
visible, we presented the area of the peaks as a function of the irradiation dose in Fig.4.
Radiation Dose Vs. Area

1.2

ES

358h(NRNF)G71h(NRNF)

CS

Area [Arb. units]

0.8Intensity(a.u)

100130ETHCSES
Assymetrical ES
Se-Se

30

1.0

Se-Se

0.60.40.2

25
2015
1050.050

100150200

250

3000350

Wavenumber(cm-1)

51015Radiation Dose [Arb. units]

Fig. 3Fig. 4.

One can discern from these results that the structure condenses through formation of a higher number of ESstructures but on the other hand these structures are connected with longer Se chains which decreases thedensity of the films. Comparing these results to our previous studies related to proton irradiation it comes outthat the influence of neutron flux irradiating the samples through a gamma ray filter is lower compared to thisof protons. This is especially true for the bi-layered structures containing a film of silver. The first indication
for this is coming from the study of the Raman spectra of these bi-layered structures. In case of proton
irradiation silver surface deposition occurs which completely wipes off the signal due to formation of a medium
with a quite high conductivity. So, in the case of proton irradiation no Raman spectra of the films could beread. This was not the case at neutron irradiation. We suggest that the charge related to the protons is areason for their stronger influence over the chalcogenide films.

Ag8GeSe6
8 hr. irrradiation

1 hr. irrradiation30

-Ag2Se

Ag8GeSe6

8 hr. irrradiation
1 hr. irrradiation
Control

Control
20c) Ge44.3Se55.7402 ()

5060

2030

Ag8GeSe6

Intensity

-Ag2Seb) Ge36.2Se63.8

Intensity

Intensitya) Ge25.6Se74.4

-Ag2SeAg

8 hr. irrradiation
1 hr. irrradiation
Control402 ()50602030405060

2 ()

Fig. 5.
Fig.5 shows the result of X-ray diffraction. The composition forming after Ag diffusion into the chalcogenidefilms, caused by irradiation shows formation of the three component composition Ag8GeSe6 whose clusters
grow with the increasing the irradiation intensity and Ge content in the samples. One interesting results isformation of Ag2Se which is stable at temperature above 133oC. We suggest that the reason for this is thefact that this composition forms within the existing structure of the chalcogenide film, which requires theclosest packed structure to form.
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