Long-term radiation-induced optical darkening effects in chalcogenide glasses
In this work, it is reported that the γ-irradiated (2.41 MGy accumulated dose) glasses As₂S₃ (∼2 mm thick) and Ge₁₅.₈As₂₁S₆₃.₂ (∼1 mm thick), both measured ∼10 years after γ-irradiation, exhibit radiation-induced optical darkening effect (i.e., long-wave shift of fundamental optical absorption edge)...
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Kavetskyy, T.S. 2017-06-15T09:25:27Z 2017-06-15T09:25:27Z 2016 Long-term radiation-induced optical darkening effects in chalcogenide glasses / T.S. Kavetskyy // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2016. — Т. 19, № 4. — С. 395-398. — Бібліогр.: 20 назв. — англ. 1560-8034 DOI: 10.15407/spqeo19.04.395 PACS 61.43.Fs, 61.80.Ed, 78.40.Fy, 78.40.Pg https://nasplib.isofts.kiev.ua/handle/123456789/121681 In this work, it is reported that the γ-irradiated (2.41 MGy accumulated dose) glasses As₂S₃ (∼2 mm thick) and Ge₁₅.₈As₂₁S₆₃.₂ (∼1 mm thick), both measured ∼10 years after γ-irradiation, exhibit radiation-induced optical darkening effect (i.e., long-wave shift of fundamental optical absorption edge). In the case of As₂S₃ glass, the observed longterm radiation-induced optical darkening effect is well comparable with that reported in literature for γ-irradiated (∼3 MGy accumulated dose) glass As₂S₃ (1.5 mm thick), measured directly after γ-irradiation. In view of practical application, this finding demonstrates the possibilities for development of innovative chalcogenide glass based long-term dosimeter systems with stable and controlled parameters. A possible general criterion for mechanisms of long-term radiation-induced structural changes in chalcogenide glasses has been also considered. The investigated samples used for measurements were prepared within joint research projects (#0106U007386 and #0109U007446c) between DSPU (Drohobych, Ukraine) and SRC “Carat” (Lviv, Ukraine) supported by the MES of Ukraine (#0106U007385 and #0109U007445). Support of DAAD (Germany) and MES of Ukraine (projects #0111U001021 and #0114U002616) is also gratefully acknowledged. en Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України Semiconductor Physics Quantum Electronics & Optoelectronics Long-term radiation-induced optical darkening effects in chalcogenide glasses Article published earlier |
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Long-term radiation-induced optical darkening effects in chalcogenide glasses |
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Long-term radiation-induced optical darkening effects in chalcogenide glasses Kavetskyy, T.S. |
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Long-term radiation-induced optical darkening effects in chalcogenide glasses |
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Long-term radiation-induced optical darkening effects in chalcogenide glasses |
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Long-term radiation-induced optical darkening effects in chalcogenide glasses |
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Long-term radiation-induced optical darkening effects in chalcogenide glasses |
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long-term radiation-induced optical darkening effects in chalcogenide glasses |
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Kavetskyy, T.S. |
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Kavetskyy, T.S. |
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2016 |
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
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In this work, it is reported that the γ-irradiated (2.41 MGy accumulated dose) glasses As₂S₃ (∼2 mm thick) and Ge₁₅.₈As₂₁S₆₃.₂ (∼1 mm thick), both measured ∼10 years after γ-irradiation, exhibit radiation-induced optical darkening effect (i.e., long-wave shift of fundamental optical absorption edge). In the case of As₂S₃ glass, the observed longterm radiation-induced optical darkening effect is well comparable with that reported in literature for γ-irradiated (∼3 MGy accumulated dose) glass As₂S₃ (1.5 mm thick), measured directly after γ-irradiation. In view of practical application, this finding demonstrates the possibilities for development of innovative chalcogenide glass based long-term dosimeter systems with stable and controlled parameters. A possible general criterion for mechanisms of long-term radiation-induced structural changes in chalcogenide glasses has been also considered.
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1560-8034 |
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https://nasplib.isofts.kiev.ua/handle/123456789/121681 |
| citation_txt |
Long-term radiation-induced optical darkening effects in chalcogenide glasses / T.S. Kavetskyy // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2016. — Т. 19, № 4. — С. 395-398. — Бібліогр.: 20 назв. — англ. |
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2025-11-24T06:16:35Z |
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2025-11-24T06:16:35Z |
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| fulltext |
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2016. V. 19, N 4. P. 395-398.
doi: https://doi.org/10.15407/spqeo19.04.395
© 2016, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
395
PACS 61.43.Fs, 61.80.Ed, 78.40.Fy, 78.40.Pg
Long-term radiation-induced optical darkening effects
in chalcogenide glasses
T.S. Kavetskyy
Drohobych Ivan Franko State Pedagogical University,
24, I. Franko str., 82100 Drohobych, Ukraine
The John Paul II Catholic University of Lublin,
14, Al. Racławickie, 20-950 Lublin, Poland
Abstract. In this work, it is reported that the γ-irradiated (2.41 MGy accumulated dose)
glasses As2S3 (∼2 mm thick) and Ge15.8As21S63.2 (∼1 mm thick), both measured ∼10 years
after γ-irradiation, exhibit radiation-induced optical darkening effect (i.e., long-wave shift
of fundamental optical absorption edge). In the case of As2S3 glass, the observed long-
term radiation-induced optical darkening effect is well comparable with that reported in
literature for γ-irradiated (∼3 MGy accumulated dose) glass As2S3 (1.5 mm thick),
measured directly after γ-irradiation. In view of practical application, this finding
demonstrates the possibilities for development of innovative chalcogenide glass based
long-term dosimeter systems with stable and controlled parameters. A possible general
criterion for mechanisms of long-term radiation-induced structural changes in
chalcogenide glasses has been also considered.
Keywords: chalcogenide glasses, optical properties, radiation modification.
Manuscript received 20.06.16; revised version received 05.09.16; accepted for
publication 16.11.16; published online 05.12.16.
1. Introduction
Radiation-induced optical effects (RIOEs) caused by
60Co γ-irradiation in chalcogenide glasses (ChGs) are
well-known to be used for dosimetric applications [1, 2].
RIOEs could be also considered as the main control
parameter of radiation sensitivity of ChGs. It has been
established on the example of Ge-As-S [3] and Ge-Sb-S
[4] systems that the total RIOEs consist of two
components: the dynamic component that relaxes for 2-3
months after γ-irradiation and static one that remains
stable for a long period of time after γ-irradiation.
Recently, analyzing the radiation-induced effects in
chalcogenide glasses the authors [5] made assumption
that a long-term period (more than 7 years) after 60Co γ-
irradiation does not give an argument for observation of
radiation-induced effects caused by timing relaxation of
post-radiation changes or dynamic component of RIOE.
But, as mentioned above, it has been experimentally
established [3, 4] that the RIOE’s dynamic component is
only 2 to 3 months and RIOE’s static component takes
place for a long period after γ-irradiation. However, the
question “how long RIOE’s static component would be
existed?” was not examined yet.
In this Letter, the results of optical transmission
measurements of As2S3 (∼2 mm thick) and Ge15.8As21S63.2
(∼1 mm thick) glasses in unirradiated and γ-irradiated
(2.41 MGy accumulated dose) states in the range of
fundamental optical absorption edge are reported for the
samples measured ∼10 years after γ-irradiation.
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2016. V. 19, N 4. P. 395-398.
doi: https://doi.org/10.15407/spqeo19.04.395
© 2016, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
396
The investigated samples of As2S3 and
Ge15.8As21S63.2 compositions were prepared from
elements of 99.9999% purity in evacuated silica
ampoules using the standard melt-quenching procedure
[6], polished to a high optical quality and annealed at
about 20…30 K below the corresponding glass transition
temperature before their radiation treatment. Both
samples were subjected to radiation treatment with 60Co
γ-quanta with the average energy E = 1.25 MeV and
accumulated dose Φ = 2.41 MGy, details of which are
described elsewhere [7-9]. Optical transmission spectra
of the samples were measured in the visible spectral
range at room temperature using an Evolution 220 UV-
visible spectrophotometer.
Fig. 1 shows the optical transmission spectra, τ(λ),
of g-As2S3 and g-Ge15.8As21S63.2 samples in the
unirradiated and γ-irradiated states, measured ∼10 years
after γ-irradiation. Clearly, the long-wave shift of
fundamental optical absorption edge is detected,
signifying the existence of long-term radiation-induced
optical darkening effect. The decrease in the sample’s
transparency in the saturation region for g-As2S3 is due to
the radiation-induced oxidation processes occurring on the
sample surface [9]. The observed long-term radiation-
induced optical darkening effect is found to be practically
the same as that reported for γ-irradiated (∼3 MGy
accumulated dose) g-As2S3 (1.5 mm thick), measured
directly after γ-irradiation [10]. To quantify this similarity,
as an example, one may compare Δτ ∼15% at λ = 675 nm
in this study (see Fig. 1) with Δτ ∼20% at λ = 675 nm in
the work [10] (see Fig. 1, curves 1 and 2). Taking into
account the dynamic RIOE component on the level of
∼5% [3, 4], it means that the RIOE’s static component
may exist for a long period, perhaps more than 10 years. It
may also indicate that a backward measuring chronology
mentioned by the authors [10], it is not necessary to be
performed, being although useful to make in situ
experiment, as the radiation-induced optical darkening
effects in chalcogenide glasses are stable in time, and
corresponding radiation-induced structural changes can be
correctly investigated with a long-time interval. In this
respect, the long-term radiation-induced structural
changes examined in the works [2, 11-14] are very
important in view of practical applications of
chalcogenide glasses. In particular, the long-term
radiation-induced effects demonstrate the possibilities for
development of innovative chalcogenide glass based long-
term dosimeter systems with stable and controlled
parameters.
In spite of the long-term radiation-induced optical
darkening effects detected in this study for both
investigated g-As2S3 and g-Ge15.8As21S63.2, the
mechanisms of long-term radiation-induced structural
changes in these compounds are found to be different [2,
11, 13, 14]. It is concluded from the recent positron
annihilation spectroscopy measurements with the
Doppler broadening of annihilation line (DBAL)
technique [11, 14]. Namely, it has been ascertained
using the DBAL data that the defect structures of
radiation-modified g-As2S3 and g-Ge15.8As21S63.2 are
different probably as a result of different mechanisms of
radiation-induced defect formation. It has been
suggested that the non-defective mechanism within the
distortion model for g-As2S3 and the defective
mechanism within the coordination topological defects
(CTDs) model for g-Ge15.8As21S63.2 took place [11, 14],
since the latter CTD model has been evidently verified
using Raman spectroscopy studies, employing the
differential representation of depolarized Raman spectra
[13]. The CTD approach used for g-Ge15.8As21S63.2 or
(As2S3)0.4(GeS2)0.6 alloy with the dominant Ge-S sub-
system seems to be valid for major Ge-S based
chalcogenides (see, for example, [15-17]).
Therefore, the positron annihilation spectroscopy
DBAL method should be reported as a highly sensitive
and unique experimental tool to compensate
impossibilities (if any) of optical and structural techniques
to directly identify the radiation-induced changes in defect
structure of glassy materials on the nanoscale level.
Moreover, analyzing the DBAL experimental results
obtained in the context with XRD and Raman data, some
regularity could be observed that may be applied to
estimate a possible general criterion for mechanisms of
long-term radiation-induced structural changes in ChGs.
Fig. 1. Optical transmission spectra, τ(λ), of (a) g-As2S3 (d ≅
2.0 mm, Φ = 2.41 MGy) and (b) g-Ge15.8As21S63.2 (d ≅ 1.0 mm,
Φ = 2.41 MGy) samples in unirradiated (unirrad.) and γ-
irradiated (irrad.) states, measured ∼10 years after γ-irradiation.
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2016. V. 19, N 4. P. 395-398.
doi: https://doi.org/10.15407/spqeo19.04.395
© 2016, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
397
Indeed, on the one hand, the established for As-S
based glasses the long-term radiation-induced structural
changes in DBAL data [2, 11, 14], when the first sharp
diffraction peak (FSDP) becomes weaker and broader
after γ-irradiation [2, 12], have been interpreted within
the non-defective distortion model. Since the FSDP
originates as a signature of the medium-range order
(MRO) structure within the range 5…20 Å in covalent
glasses (for review, see [18]), which is commonly
accepted by many researchers in literature, the FSDP
weakening and broadening means the decrease in the
MRO structural correlation length and, consequently, the
rise of disordering on the MRO scale. Note, that no
changes or possible ordering on the short-range order
(SRO) structure within the range 2 to 5 Å [18] should be
happened as a result of radiation-induced decreasing the
size or void concentration due to relaxation processes
within the distortion model [14]. Thus, when the
radiation-induced structural changes in ChGs occur
towards the disordering on the MRO scale and no changes
or ordering on the SRO scale, the non-defective
mechanism in the frame of the distortion model and any
other models (if exist), resulting in a final structural
configuration without charged defects, is dominant. On
the other hand, the established for Ge-S based glasses the
long-term radiation-induced structural changes in DBAL
data [2, 11, 14], when the FSDP remains practically
unchanged [2] or its intensity can be something higher
[16] and peak is probably something narrower upon γ-
irradiation, have been interpreted within the defective
CTD model, involving atomic rearrangements directly in
the first coordination shells (first-nearest-neighbor atomic
correlations), that is, on the SRO scale. The unobservable
changes in the FSDP and/or the FSDP sharping and
narrowing means that no changes or increasing the MRO
structural correlation length and, consequently, a stable
MRO structure and/or rise of ordering on the MRO scale
take place. Thus, when the radiation-induced structural
changes in ChGs occur towards the no changes or
ordering on the MRO scale and disordering on the SRO
scale, the defective mechanism in the frame of the
coordination topological defects and any other models (if
exist), resulting in a final structural configuration with
charged defects, is dominant.
The above mentioned DBAL data versus FSDP-
XRD data, interpreted within CTD model for g-
Ge15.8As21S63.2, are also found to be consistent with
Raman data, showing clear confirmation for CTD model
applied [13]. In view of the above analysis, the degree of
disorder, exemplified by the ratio of Ibos/Imol in Raman
spectrum, illustrating the essential increase of the degree
of disorder after γ-irradiation for g-Ge15.8As21S63.2 [13],
should be related to the increase in the disorder on the
SRO scale in agreement again with CTD approach. Thus,
the origin of Ibos/Imol seems to be related with the degree of
disorder of SRO structure in covalent glasses. It is also
some signature that the first sharp diffraction peak and the
low frequency dynamics (the boson peak) are not related
directly to each other on the MRO scale, which is in
contrast to assumption made by the authors [19] and in
agreement with observations of the authors [20].
Let us summarize the possible general criterion for
mechanisms of long-term radiation-induced structural
changes in chalcogenide glasses that involves “ordering-
disordering” on the nanoscale as follows: when the
radiation-induced structural changes in chalcogenide
glasses occur towards disordering on the medium-range
order scale and no changes or ordering on the short-
range order scale, the non-defective mechanism, resulting
in a final structural configuration without charged
defects, is dominant; and, vice versa, when the radiation-
induced structural changes in chalcogenide glasses occur
towards no changes or ordering on the medium-range
order scale and disordering on the short-range order
scale, the defective mechanism, resulting in a final
structural configuration with charged defects, is
dominant.
In conclusion, the long-term radiation-induced
optical darkening effects have been detected for g-As2S3
(d ≅ 2.0 mm, Φ = 2.41 MGy) and g-Ge15.8As21S63.2 (d ≅
1.0 mm, Φ = 2.41 MGy), measured ∼10 years after γ-
irradiation. In the case of g-As2S3, the observed long-
term radiation-induced optical darkening effect is well
comparable with that reported in literature for γ-
irradiated (∼3 MGy accumulated dose) g-As2S3 (1.5 mm
thick) measured directly after γ-irradiation [10]. In view
of practical applications, this finding demonstrates the
possibilities for development of innovative chalcogenide
glass based long-term dosimeter systems with stable and
controlled parameters. Previous investigations of both
these samples with the positron annihilation
spectroscopy DBAL method and analysis performed in
respect to XRD and Raman data allow also suggestion
on the possible general criterion for mechanisms of long-
term radiation-induced structural changes in ChGs.
Acknowledgments
The investigated samples used for measurements were
prepared within joint research projects (#0106U007386
and #0109U007446c) between DSPU (Drohobych,
Ukraine) and SRC “Carat” (Lviv, Ukraine) supported by
the MES of Ukraine (#0106U007385 and
#0109U007445). Support of DAAD (Germany) and
MES of Ukraine (projects #0111U001021 and
#0114U002616) is also gratefully acknowledged.
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Semiconductor Physics, Quantum Electronics & Optoelectronics, 2016. V. 19, N 4. P. 395-398.
doi: https://doi.org/10.15407/spqeo19.04.395
© 2016, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
398
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