The paper describes the research of temperature effect of potassium-alumina-borate (PAB) glass with
CuBr nanocrystals, which was obtained in optical wavelength region for the first time. Temperature dependence
of optical density at different wavelengths was examined. Melting and crystallization temperatures
were evaluated for different nanocrystals sizes. Great changes of exciton absorption band influenced
by temperatures below 100°C were recorded. Propositions for studied glass application as tunable filters in
electro-optic circuit were suggested.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3542

Babkina, A.N.

Nikonorov, N.V.

Shirshnev, P.S.

Tsekhomsky, B.A.

Electronic Sumy State University Institutional Repository

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  NANOMATERIALS: APPLICATIONS AND PROPERTIES Vol. 2 No 2, 02NNPA02(2pp) (2013)   2304-1862/2013/2(Ошибка! Источник ссылки не найден.)02NNPA02(2) 02NNPA02-1  2013 Sumy State University Temperature Effect on Exciton Absorption of CuBr Nanocrystals in Potassium-alumina-borate Glass  A.N. Babkina, P.S. Shirshnev, B.A. Tsekhomsky, N.V. Nikonorov  Saint-Petersburg National Research University of Information Technologies, Mechanics and Optics,  49, Kronverkskiy pr., 197101 Saint-Petersburg, Russia  (Received 21 May 2013; published online 31 August 2013)  The paper describes the research of temperature effect of potassium-alumina-borate (PAB) glass with CuBr nanocrystals, which was obtained in optical wavelength region for the first time. Temperature de-pendence of optical density at different wavelengths was examined. Melting and crystallization tempera-tures were evaluated for different nanocrystals sizes. Great changes of exciton absorption band influenced by temperatures below 100°C were recorded. Propositions for studied glass application as tunable filters in electro-optic circuit were suggested.  Keywords: CuBr nanocrystals, Exciton absorption band, Temperature dependence, Melting and crystalli-zation temperature, Tunable filter.   PACS numbers: 71.35.Cc, 07.20.Dt  1. INTRODUCTION  Glasses with CuHal nanocrystals are known as ma-terial for optical filters in near UV region. Due to the large exciton binding energy the exciton absorption band has a very steep border [1,2]. Until recently borosilicate glasses with CuHal nanocrystals were only known. They have photochromic properties. Couples of years ago in the walls of our department new glasses with CuHal nanocrystals were obtained. They had PAB matrix and were not photochromic. Small angle X-ray scattering (SAXS) of these glasses showed quite unusual results while sample heating and cooling [3]. After that the de-cision of studying temperature influence on exciton ab-sorption band of CuHal nanocrystals were accepted.  2. OBJECT OF RESEARCH  The paper examines PAB glasses with CuBr nano-crystals. The nanocrystals extraction took place during isothermal heat treatment. Glass transition tempera-ture was defined by means of differential scanning cal-orimetry. Thermal heating was carrying out at temper-atures above glass transition one during 10 hours. Af-ter heat treatment absorption spectra of samples were registered on spectrophotometer Lambda 650 (by Per-kin Elmer) (Fig. 1).  3. CHARACTERISTIC TEMPERATURES EVAL-UATION   Optical density spectra were registered using a fi-ber spectrometer (by Avalar) while linear heating and cooling of samples every 0,3° increment. Heating and cooling of samples were carried out in thermal cell (portable oven).   3.1 Results of experiments  For each sample the location of exciton absorption band was defined. During heating and cooling of sam-ples it does not change. So the temperature dependenc-es of optical density in the wavelength of maximum of exciton absorption band were obtained (Fig. 2).   Fig. 1 – Absorption coefficients spectra of samples with differ-ent temperatures of thermal heating: 1 – initial sample, 2 - 390°C, 3 - 440°C, 4 - 450°C    Fig. 2 – Temperature dependence of optical density for sam-ple2 on 395nm: 1 – heating, 2 – cooling. T1 – temperature of melting ending, T2 – temperature of crystallization beginning   A.N. BABKINA, P.S. SHIRSHNEV, B.A. TSEKHOMSKY, N.V. NIKONOROV PROC. NAP 2, 02NNPA02 (2013)   02NNPA02-2 Compared to studies on borosilicate glasses [1,2], melting and crystallization temperatures are much low-er. Melting point increases from 189°C to 236°C with the increase of temperature of sample heat treatment from 390°C to 450°C. So does happen with the crystallization temperature. It rises from 77°C to 105°C.  3.2 Discussion  The increase of the melting temperature by increas-ing the heat treatment temperature is mentioned in many papers [1,2,3].Such regularity is related to the size effect: increasing radius of the nanocrystalline phase increases its melting temperature.  Due to the low melting and crystallization temper-atures these glasses can be used as a material for an optical trigger or switch. In this experiment the tem-perature of the sample surface was measured. CuBr nanocrystals can be heated to the required tempera-tures by absorbing  UV radiation with a wavelength, which coincides with the absorption band of the exci-ton of CuBr.  It will let us not to use a heating ele-ment and will protect the other components of the circuit.   4. CHANGING THE BORDER OF EXCITON AB-SORPTION BAND  4.1 Results of experiment  When samples are heated to temperatures in the beginning of the melting curve (in the region of tem-perature T4 (Fig. 2)) and then cooled down, there is a shift of the exciton absorption band towards visible region (Fig. 3). Heating sample to T4, which is close to the melting temperature, makes absorption band return to the original position. During sample heating the location of spectrum does not chang. The shift takes place during the process of sample cool-ing.   Fig. 3 – Exciton absorption band changing: 1 – initial spec-trum, after heating to 2 – T4 and 3 – T3  4.2 Discussion  While heating samples to temperatures below 100°C the border of the absorption filter can be shifted up to 5nm in the visible region. Typically, such action is using a set of multiple filters. Our glass composition allows not to use several filters for this operation, only adjusting the duration and temperature of our tunable filter heating.  5. CONCLUSION  Potassium-alumina-borate glass with CuHal nano-crystals is a new optical material, which is very promis-ing, both in terms of fundamental studies and practical application. Low temperatures of nanocrystalline phase transformations make it more accessible and easier to use than borosilicate glass.  AKNOWLEDGEMENTS  This work was supported by RFFI grant program “My first grant” for 2012-2013 (mol_a 12-02-31896).   REFERENCES  1.  A.V. Dotsenko, L.B. Glebov, V.A. Tsekhomsky, Physics and Chemistry of Photochromic Glasses(NY: CRC Press: 1998). 2. P.N. Valov, V.I.  Leiman, Physics of Solid State, 51 No81, 1607 (2009). 3. V.V. Golubkov, A.A. Kim, N.V. Nikonorov, V.A. Tsekhomskii, P.S. Shirshnev, Glass Physics and Chemistry. 38 No3, 259 (2012).  

Temperature Effect on Exciton Absorption of CuBr Nanocrystals in Potassium-aluminaborate Glass

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  
NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 2 No 2, 02NNPA02(2pp) (2013) 
 
 
2304-1862/2013/2(Ошибка! Источник ссылки не найден.)02NNPA02(2) 02NNPA02-1  2013 Sumy State University 
Temperature Effect on Exciton Absorption of CuBr Nanocrystals in Potassium-alumina-
borate Glass 
 
A.N. Babkina, P.S. Shirshnev, B.A. Tsekhomsky, N.V. Nikonorov 
 
Saint-Petersburg National Research University of Information Technologies, Mechanics and Optics,  
49, Kronverkskiy pr., 197101 Saint-Petersburg, Russia 
 
(Received 21 May 2013; published online 31 August 2013) 
 
The paper describes the research of temperature effect of potassium-alumina-borate (PAB) glass with 
CuBr nanocrystals, which was obtained in optical wavelength region for the first time. Temperature de-
pendence of optical density at different wavelengths was examined. Melting and crystallization tempera-
tures were evaluated for different nanocrystals sizes. Great changes of exciton absorption band influenced 
by temperatures below 100°C were recorded. Propositions for studied glass application as tunable filters in 
electro-optic circuit were suggested. 
 
Keywords: CuBr nanocrystals, Exciton absorption band, Temperature dependence, Melting and crystalli-
zation temperature, Tunable filter. 
 
 PACS numbers: 71.35.Cc, 07.20.Dt 
 
1. INTRODUCTION 
 
Glasses with CuHal nanocrystals are known as ma-
terial for optical filters in near UV region. Due to the 
large exciton binding energy the exciton absorption band 
has a very steep border [1,2]. Until recently borosilicate 
glasses with CuHal nanocrystals were only known. They 
have photochromic properties. Couples of years ago in 
the walls of our department new glasses with CuHal 
nanocrystals were obtained. They had PAB matrix and 
were not photochromic. Small angle X-ray scattering 
(SAXS) of these glasses showed quite unusual results 
while sample heating and cooling [3]. After that the de-
cision of studying temperature influence on exciton ab-
sorption band of CuHal nanocrystals were accepted. 
 
2. OBJECT OF RESEARCH 
 
The paper examines PAB glasses with CuBr nano-
crystals. The nanocrystals extraction took place during 
isothermal heat treatment. Glass transition tempera-
ture was defined by means of differential scanning cal-
orimetry. Thermal heating was carrying out at temper-
atures above glass transition one during 10 hours. Af-
ter heat treatment absorption spectra of samples were 
registered on spectrophotometer Lambda 650 (by Per-
kin Elmer) (Fig. 1). 
 
3. CHARACTERISTIC TEMPERATURES EVAL-
UATION  
 
Optical density spectra were registered using a fi-
ber spectrometer (by Avalar) while linear heating and 
cooling of samples every 0,3° increment. Heating and 
cooling of samples were carried out in thermal cell 
(portable oven).  
 
3.1 Results of experiments 
 
For each sample the location of exciton absorption 
band was defined. During heating and cooling of sam-
ples it does not change. So the temperature dependenc-
es of optical density in the wavelength of maximum of 
exciton absorption band were obtained (Fig. 2). 
 
 
Fig. 1 – Absorption coefficients spectra of samples with differ-
ent temperatures of thermal heating: 1 – initial sample, 2 -
 390°C, 3 - 440°C, 4 - 450°C 
 
 
 
Fig. 2 – Temperature dependence of optical density for sam-
ple2 on 395nm: 1 – heating, 2 – cooling. T1 – temperature of 
melting ending, T2 – temperature of crystallization beginning 
 
 A.N. BABKINA, P.S. SHIRSHNEV, B.A. TSEKHOMSKY, N.V. NIKONOROV PROC. NAP 2, 02NNPA02 (2013) 
 
 
02NNPA02-2 
Compared to studies on borosilicate glasses [1,2], 
melting and crystallization temperatures are much low-
er. Melting point increases from 189°C to 236°C with the 
increase of temperature of sample heat treatment from 
390°C to 450°C. So does happen with the crystallization 
temperature. It rises from 77°C to 105°C. 
 
3.2 Discussion 
 
The increase of the melting temperature by increas-
ing the heat treatment temperature is mentioned in 
many papers [1,2,3].Such regularity is related to the size 
effect: increasing radius of the nanocrystalline phase 
increases its melting temperature.  
Due to the low melting and crystallization temper-
atures these glasses can be used as a material for an 
optical trigger or switch. In this experiment the tem-
perature of the sample surface was measured. CuBr 
nanocrystals can be heated to the required tempera-
tures by absorbing  UV radiation with a wavelength, 
which coincides with the absorption band of the exci-
ton of CuBr.  It will let us not to use a heating ele-
ment and will protect the other components of the 
circuit.  
 
4. CHANGING THE BORDER OF EXCITON AB-
SORPTION BAND 
 
4.1 Results of experiment 
 
When samples are heated to temperatures in the 
beginning of the melting curve (in the region of tem-
perature T4 (Fig. 2)) and then cooled down, there is 
a shift of the exciton absorption band towards visible 
region (Fig. 3). Heating sample to T4, which is close 
to the melting temperature, makes absorption band 
return to the original position. During sample 
heating the location of spectrum does not chang. The 
shift takes place during the process of sample cool-
ing. 
 
 
Fig. 3 – Exciton absorption band changing: 1 – initial spec-
trum, after heating to 2 – T4 and 3 – T3 
 
4.2 Discussion 
 
While heating samples to temperatures below 100°C 
the border of the absorption filter can be shifted up to 
5nm in the visible region. Typically, such action is using 
a set of multiple filters. Our glass composition allows not 
to use several filters for this operation, only adjusting the 
duration and temperature of our tunable filter heating. 
 
5. CONCLUSION 
 
Potassium-alumina-borate glass with CuHal nano-
crystals is a new optical material, which is very promis-
ing, both in terms of fundamental studies and practical 
application. Low temperatures of nanocrystalline phase 
transformations make it more accessible and easier to 
use than borosilicate glass. 
 
AKNOWLEDGEMENTS 
 
This work was supported by RFFI grant program 
“My first grant” for 2012-2013 (mol_a 12-02-31896). 
 
 
REFERENCES 
 
1.  A.V. Dotsenko, L.B. Glebov, V.A. Tsekhomsky, Physics 
and Chemistry of Photochromic Glasses(NY: CRC Press: 
1998). 
2. P.N. Valov, V.I.  Leiman, Physics of Solid State, 51 No81, 
1607 (2009). 
3. V.V. Golubkov, A.A. Kim, N.V. Nikonorov, 
V.A. Tsekhomskii, P.S. Shirshnev, Glass Physics and 
Chemistry. 38 No3, 259 (2012). 
 


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Temperature Effect on Exciton Absorption of CuBr Nanocrystals in Potassium-aluminaborate Glass

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