Ion exchange in photoactivated inorganic matters
The effects of monovalent and bivalent impurities on the diffusive mobility sodium, caesium and strontium in magnesium potassium phosphate hexahydrate and clinoptilolite were analysed. It was determined that ratio of diffusion coeffcients of sodium concerning caesium and strontium are in antagonisti...
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| Zitieren: | Ion exchange in photoactivated inorganic matters / N.P. Dikiy, A.N. Dovbnya, Yu.V. Lyashko, D.V. Medvedev, E.P. Medvedeva, Yu.G. Parhomenko, V.L. Uvarov, I.D. Fedorets // Вопросы атомной науки и техники. — 2017. — № 3. — С. 40-44. — Бібліогр.: 13 назв. — англ. |
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nasplib_isofts_kiev_ua-123456789-1360642025-02-09T14:13:17Z Ion exchange in photoactivated inorganic matters Іонний обмін у фотоактивованих неорганічних речовинах Ионный обмен в фотоактивированных неорганических веществах Dikiy, N.P. Dovbnya, A.N. Lyashko, Yu.V. Medvedev, D.V. Medvedeva, E.P. Parhomenko, Yu.G. Uvarov, V.L. Fedorets, I.D. Ядерно-физические методы и обработка данных The effects of monovalent and bivalent impurities on the diffusive mobility sodium, caesium and strontium in magnesium potassium phosphate hexahydrate and clinoptilolite were analysed. It was determined that ratio of diffusion coeffcients of sodium concerning caesium and strontium are in antagonistic dependence on the caesium and strontium content in a matrices on the basis of magnesium potassium phosphate hexahydrate. It is established that the diffusion process in the magnesium potassium phosphate hexahydrate is due to the Frenkel. The influence of the diffusion of impurity elements as a function of the ionic radius and the ion position in the crystal lattice of clinoptilolite has been studied. Проаналізовано вплив моновалентних і двовалентних домішок на дифузійну рухливість натрію, цезію і стронцію в гексагідраті фосфату калію магнію. Визначено, що відношення коефіцієнтів дифузії натрію щодо цезію і стронцію знаходяться в антагоністичній залежності від вмісту цезію і стронцію в матрицях на основі гексагідраті фосфату калію магнію. Встановлено, що дифузійний процес у гексагідраті фосфату калію магнію обумовлений механізмом Френкеля. Вивчено вплив дифузії домішкових елементів в залежності від іонного радіуса і займаної позиції в кристалічній решітці кліноптілоліта. Проанализировано влияние моновалентных и двухвалентных примесей на диффузионную подвижность натрия, цезия и стронция в гексагидрате фосфата калия магния. Определено, что отношения коэффициентов диффузии натрия относительно цезия и стронция находятся в антагонистической зависимости от содержания цезия и стронция в матрицах на основе гексагидрата фосфата калия магния. Установлено, что диффузионный процесс в гексагидрате фосфата магния обусловлен механизмом Френкеля. Изучено влияние диффузии примесных элементов в зависимости от ионного радиуса и занимаемой позиции в кристаллической решетке клиноптилолита. 2017 Article Ion exchange in photoactivated inorganic matters / N.P. Dikiy, A.N. Dovbnya, Yu.V. Lyashko, D.V. Medvedev, E.P. Medvedeva, Yu.G. Parhomenko, V.L. Uvarov, I.D. Fedorets // Вопросы атомной науки и техники. — 2017. — № 3. — С. 40-44. — Бібліогр.: 13 назв. — англ. 1562-6016 PACS: 66.30.-h; 81.05.Rm https://nasplib.isofts.kiev.ua/handle/123456789/136064 en Вопросы атомной науки и техники application/pdf Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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Ядерно-физические методы и обработка данных Ядерно-физические методы и обработка данных |
| spellingShingle |
Ядерно-физические методы и обработка данных Ядерно-физические методы и обработка данных Dikiy, N.P. Dovbnya, A.N. Lyashko, Yu.V. Medvedev, D.V. Medvedeva, E.P. Parhomenko, Yu.G. Uvarov, V.L. Fedorets, I.D. Ion exchange in photoactivated inorganic matters Вопросы атомной науки и техники |
| description |
The effects of monovalent and bivalent impurities on the diffusive mobility sodium, caesium and strontium in magnesium potassium phosphate hexahydrate and clinoptilolite were analysed. It was determined that ratio of diffusion coeffcients of sodium concerning caesium and strontium are in antagonistic dependence on the caesium and strontium content in a matrices on the basis of magnesium potassium phosphate hexahydrate. It is established that the diffusion process in the magnesium potassium phosphate hexahydrate is due to the Frenkel. The influence of the diffusion of impurity elements as a function of the ionic radius and the ion position in the crystal lattice of clinoptilolite has been studied. |
| format |
Article |
| author |
Dikiy, N.P. Dovbnya, A.N. Lyashko, Yu.V. Medvedev, D.V. Medvedeva, E.P. Parhomenko, Yu.G. Uvarov, V.L. Fedorets, I.D. |
| author_facet |
Dikiy, N.P. Dovbnya, A.N. Lyashko, Yu.V. Medvedev, D.V. Medvedeva, E.P. Parhomenko, Yu.G. Uvarov, V.L. Fedorets, I.D. |
| author_sort |
Dikiy, N.P. |
| title |
Ion exchange in photoactivated inorganic matters |
| title_short |
Ion exchange in photoactivated inorganic matters |
| title_full |
Ion exchange in photoactivated inorganic matters |
| title_fullStr |
Ion exchange in photoactivated inorganic matters |
| title_full_unstemmed |
Ion exchange in photoactivated inorganic matters |
| title_sort |
ion exchange in photoactivated inorganic matters |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2017 |
| topic_facet |
Ядерно-физические методы и обработка данных |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/136064 |
| citation_txt |
Ion exchange in photoactivated inorganic matters / N.P. Dikiy, A.N. Dovbnya, Yu.V. Lyashko, D.V. Medvedev, E.P. Medvedeva, Yu.G. Parhomenko, V.L. Uvarov, I.D. Fedorets // Вопросы атомной науки и техники. — 2017. — № 3. — С. 40-44. — Бібліогр.: 13 назв. — англ. |
| series |
Вопросы атомной науки и техники |
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| fulltext |
ION EXCHANGE IN PHOTOACTIVATED INORGANIC
MATTERS
N.P. Dikiy1∗, A.N.Dovbnya1, Yu.V.Lyashko1, D.V.Medvedev1,
E.P.Medvedeva1, Yu.G.Parhomenko1, V.L.Uvarov1, I.D.Fedorets2
1National Science Center "Kharkiv Institute of Physics and Technology", 61108, Kharkiv, Ukraine;
2V.N. Karazin Kharkiv National University, 61077, Kharkiv, Ukraine
(Received April 31, 2017)
The e�ects of monovalent and bivalent impurities on the di�usive mobility sodium, caesium and strontium in mag-
nesium potassium phosphate hexahydrate and clinoptilolite were analysed. It was determined that ratio of di�usion
coe�cients of sodium concerning caesium and strontium are in antagonistic dependence on the caesium and strontium
content in a matrices on the basis of magnesium potassium phosphate hexahydrate. It is established that the di�usion
process in the magnesium potassium phosphate hexahydrate is due to the Frenkel. The in�uence of the di�usion of
impurity elements as a function of the ionic radius and the ion position in the crystal lattice of clinoptilolite has been
studied.
PACS: 66.30.-h; 81.05.Rm
1. INTRODUCTION
The present article compares the more important nat-
ural zeolite and ceramic based material (MgKPO4)
for the immobilization of ion Cs+. There have been
many articles published both on zeolite and magne-
sium potassium phosphate hydrate which devoted to
this problem, however, the use of radiation to modify
the properties of these materials is relatively unre-
ported [1-3].
Zeolites are inorganic solids consisting of enclosed
regular cavities or channels of well-de�ned size and
shape that are widely used in industry in separation
processes, such as catalysts and in nanoreactors [4].
A major diversity of properties of zeolites is caused by
its structural singularities. The crystalline skeleton,
for example, clinoptilolite, consists of tetrahedrons
[(Si,Al)O4] and has a substrati�ed constitution and
two-dimensional system of channels. In this skele-
ton which has the subzero charge, the part of ions
Si4+ is substituted by ions Al3+, that is compen-
sated by presence of such cations as Na+, K+, Ca2+,
Mg2+, etc. These cations can easily be substituted
by cations of other metals. Canals and vacuities of
a crystalline skeleton clinoptilolite are �lled ¾zeolite
water¿. In case of a dehydration of ¾zeolite water¿,
clinoptilolite is selective sorbent of Cs+ and Sr2+ ions
at the expense of coincidence of the dimensions of hol-
lows of a clinoptilolite skeleton and of ionic radii of
Cs+ (0.181 nm) and Sr2+ (0.132 nm). The kinetic
characteristic of a sorption consists of interior dif-
fusion of ions with coe�cient ∼10−11 cm2/s and of
exterior di�usion with coe�cient ∼10−5 cm2/s. Tak-
ing into account it, nanosize of clinoptilolite particles
leads to increase of a rate of an ion exchange and to
rise of adsorption capacity.
Potassium magnesium phosphate hydrate are
formed by reaction between magnesium oxide (MgO)
and potassium dihydrogen phosphate (KH2PO4) in
solution governed by reaction: MgO + KH2PO4 +
5H2O→MgKPO4·6H2O Such potassium magnesium
phosphate hydrate have good mechanical strengths,
good chemical stability and can be used for immobi-
lization of radioactive waste in other matrices.
The irradiating of magnesium potassium phos-
phate hexahydrate in�uences the ionic exchange
which has some the singularities [5] (Table 1). With
an increase of an exposure dose the process of a leach-
ing of ions from magnesium potassium phosphate
hexahydrate decreases owing to structural modi�ca-
tions.
Table 1. The loss weight of ceramic samples after
leaching during 858 hours, %
Leaching samples Loss weight Irradiation
KE+10%CaSiO3 14.6% e− 100 MGy
+0.3%H3BO3
KW+10%CaSiO3 18.5% e− 100 MGy
+0.3%H3BO3
KW+10%CaSiO3 19.9% γ 1 MGy
KE+10%CaSiO3 21.6% γ 1 MGy
+0.3%H3BO3
∗Corresponding author E-mail address: ndikiy@kipt.kharkov.ua
40 ISSN 1562-6016. PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY, 2017, N3(109).
Series: Nuclear Physics Investigations (68), p.40-44.
The essential di�erences note in the di�usion of
univalent and divalent ions. Obviously, this is con-
nected with near of Cs+ and K+ radii (0.181 and
0.152 nm, accordingly). Radius Na+ much less also
is 0.116 nm. It is necessary to notice that irradiation
of magnesium potassium phosphate hexahydrate as
by electrons, and bremsstrahlung lead to decrease of
Cs+ di�usion coe�cient at increasing of its content
in a matrix. The similar mechanism of di�usion be-
comes perceptible and for Sr2+ ion. The value of
di�usion coe�cient Sr2+ depends on the quantity of
its content in magnesium potassium phosphate. The
most considerable modi�cations of Sr2+ di�usion co-
e�cient, more than in 10 times, are observed at an
irradiating of magnesium potassium phosphate hex-
ahydrate by bremsstrahlung to doses 1 MGy.
Apparently, in the course of an irradiating of sam-
ples the part of magnesium oxide (MgO) is dissolv-
ing in phosphoric acid (Table 1) [6]. Hydration ra-
dius of Mg2+ (0.426 nm) is more than radius of Sr2+
(0.412 nm). Ions Mg2+ are in a structure of potas-
sium magnesium phosphate hydrate in the form of
an octahedron with 6 molecules of water (Fig.1).
Fig.1. Projection of the crystal structure of the
potassium analogue of struvite along the b-axis ro-
tated 180◦ in the plane of the paper. It shows that
the sites occupied by the K+ ion which, like the NH4
+
ion, lie on the (101), (103), (200), and (002) planes,
and di�raction from these planes should be most af-
fected by the replacement of NH4
+ by K+. The trace
of the 101 plane through the K+ ions is marked [7]
It transpires that a well-de�ned potassium ana-
logue [MgKPO4·6H2O] of struvite exists, where K
+
replaces the NH4
+ ammonium cations. These two
compounds are isostructural with the existence of a
complete isomorphous series from 100% K+ to 100%
NH4
+ struvite. This ion replacement is possible, as
the ionic radii of K+ and NH4
+ are almost identical
(0.152 vs 0.151 nm).
The purpose of this article is establishment of the
mechanism of di�usion of univalent ions in magne-
sium potassium phosphate hexahydrate depending on
the content of divalent elements, and also investiga-
tion of changes of value of di�usion coe�cients from
an impurity content in samples. Also, the study of
the in�uence of ion location in a crystal lattice of
clinoptilolite on their di�usion was the purpose of this
article.
2. MATERIALS AND METHODS
Samples on the basis of magnesium potas-
sium phosphate hexahydrate with imita-
tors "Hanford-1" KE basin sludge and
10%CaSiO3+0.3%H3BO3, "Hanford-1" KW basin
sludge and 10%CaSiO3+0.3%H3BO3, "Hanford-1"
KW basin sludge and 10%CaSiO3, "Hanford-1"
KE basin sludge and 10%CaSiO3+ 0.3%H3BO3
and clinoptilolite were irradiated by electrons and
bremsstrahlung to dose 100 MGy and 1 MGy, ac-
cordingly.
After an irradiation, the leaching of samples
was realized in the distilled water at tempera-
ture 37◦C. pH of the solution of leaching was 9.5.
Ge(Li)-detector was used for comparison of the
γ-spectra of these samples before and after irradia-
tion (Fig.2).
500 1000 1500
101
102
103
104
co
un
ts
channel
KW+10 CaSiO
3
+0,3H
3
BO
3
before leaching
67Ga 93 keV
511 keV
132Cs 667 keV
22Na 1275 keV
24Na 1369 keV
47Ca 1297 keV
Fig.2. Energy spectrum of the sample of potassium
magnesium phosphate hydrate after an irradiation
on the electronic accelerator before leaching [5]
3. RESULTS AND DISCUSSION
The di�usion coe�cients Na, Cs and Sr in samples of
magnesium potassium phosphate hexahydrate were
calculated from expression:
q =
2√
π
co
√
Dt ,
where D � di�usion coe�cient, co � concentration of
a studied element in substance.
41
The di�usion coe�cients of sodium in magnesium
potassium phosphate hexahydrate demonstrate high
similarity. Perhaps this is connected with a much
smaller sodium radius relative to potassium radius
(0.116 vs 0.152 nm). The ratio of the values sum of
sodium di�usion coe�cient regarding values sum of
caesium and strontium di�usion coe�cients largely
characterize the behavior of Cs+ and Sr2+ ions. It
can be seen, if the strontium content in matrix is large
then the di�usion coe�cient of caesium in matrix on
the basis of magnesium potassium phosphate hex-
ahydrate (Tab. 2) is higher. On the other hand, the
greater the amount of caesium, the greater di�usion
coe�cient of strontium in ceramics on the basis of
magnesium potassium phosphate hexahydrate. The
strontium has more strong opposite e�ect of di�usion
regarding caesium and potassium since strontium is
not isomorphic impurity in a matrix on the basis of
magnesium potassium phosphate hexahydrate.
Table 2. The sum of ratios of the di�usion coe�cients of sodium relative to caesium and strontium and
content of caesium and strontium in the ceramic samples
KE+10%CaSiO3 KW+10%CaSiO3 KW+10%CaSiO3 KE+10%CaSiO3
+0.3%H3BO3 +0.3%H3BO3 +0.3%H3BO3
electrons, 100 MGy electrons, 100 MGy γ-radiation, 1 MGy γ-radiation, 1 MGy∑
DNa/DCs 15.87 28.3 34.6 14.7
content Cs, g/g 1.6·10−4 5.25·10−4 5.15·10−4 1.7·10−4∑
DNa/DSr 15.76 5.98 2.56 32.7
content Sr, g/g 9.97·10−3 4.63·10−3 4.37·10−3 1.09·10−2
The strength of the ion-dipole interaction of
water molecules with cation decreases with in-
creasing radius of the cation coordinated by the
molecule. Therefore it can be expected that the low-
temperature di�usion will be realised in hydrate of
barium, and high-temperature � in hydrate of mag-
nesium. But in real conditions, there is no com-
plete con�rmation of this dependence on the radius
of the cations. It is necessary to notice that di�u-
sion rate depends not only on the energy state and
not only from the chemical nature of cations and an-
ions which are the nearest neighbours of a molec-
ula of water. There is another parameter, for ex-
ample, physical, or entropic which is connected with
ðàçóïîðÿäî÷åííîñòüþ in a locating of atoms. Char-
acter of atomic packaging of K, Mg and ÐÎ4 in mag-
nesium potassium phosphate hexahydrate possesses
speci�city which is bound to the extreme dimensions
of these ions. From the laws of dense atomic packing,
it is known that particles with high various sizes it
is di�cult to package in an unambiguous way. Am-
biguity in the arrangement of atoms creates intern-
odes that can participate in the formation of migra-
tion paths penetrating the whole crystal in a solid.
In other words, we can say that enhanced di�usion
in crystalline hydrates is in need of not only a suit-
able energy but also a suitable space. Such space is
in MgKPO4·6H2O. Magnesium potassium phosphate
hexahydrate has a low speci�c gravity of 1.7 g/cm3.
The content of impurities in the magnesium
potassium phosphate hexahydrate also has a signi�-
cant e�ect on di�usion processes, according to A Ly-
dyard's theory [9]. The alloying of ionic NaCl crystals
by Sr2+ ions leads to a decrease in the di�usion co-
e�cients of anions, which is proof of the presence of
Schottky defects [10]. In our case, cation di�usion
is suppressed, indicating a di�erent di�usion mech-
anism in potassium magnesium phosphate hydrate,
according to the Frenkel di�usion mechanism [11].
The ionic radius of gallium is 0.076 nm, which
is less than the ionic radii of sodium and potassium
(0.116 and 0.152 nm, respectively). Therefore, inter-
stitial gallium di�usion must be signi�cant. However,
gallium is not an isomorphic impurity in magnesium
potassium phosphate hexahydrate. Therefore, the
di�usion coe�cient of gallium in magnesium potas-
sium phosphate hexahydrate should di�er from the
di�usion coe�cients of magnesium and potassium.
The sum of the ratio
∑
DNa/DGa is less than 5%,
therefore can suggest that the di�usion of gallium
in magnesium potassium phosphate hexahydrate is
realized by another mechanism than for impurities
of sodium and caesium. Apparently, the di�usion of
sodium, caesium, potassium in magnesium potassium
phosphate hexahydrate realize by the Frenkel mech-
anism.
The di�usion coe�cients Na, Ca, K, Mn and
Rn in clinoptilolite were calculated in the same way
like for magnesium potassium phosphate hexahydrate
with use of leachate of samples (Fig.3).
On Fig. 4 the di�usion coe�cients of ions in
clinoptilolite are presented. Clinoptilolite belongs
to microporous materials and its properties are in
many respects similar magnesium potassium phos-
phate hexahydrate. Di�usion mobility in clinoptilo-
lite is in many respects determined by steric factors.
Also, it is supposed that di�usion of cations in clinop-
tilolite is realized by the interstitial mechanism de-
spite a high vacancy concentration in it [12]. The
ionic radii of sodium and potassium are equal 0.116
and 0.152 nm that determines their site and bond
with a lattice of clinoptilolite (Fig.5) [13].
42
500 1000 1500
100
101
102
co
un
ts
channel
511 keV
43K 373, 617 keV
89Zr 909 keV
22Na 1275 keV
24Na 1369 keV
40K 1461 keV
24Na'' 1732 keV
Fig.3. The energy spectrum of clinoptilolite leachate
0,0 3,0x105 6,0x105
1E-20
1E-18
1E-16
D,
m
2 /s
time, s
Na
Ca
K
Mn
Rn
x 10-8
clinoptilolite
Fig.4. Di�usion coe�cients of Na, Ca, K, Mn and
Rn in clinoptilolite
The potassium ion is in position À1 in coordination
with 6 atoms of oxygen and 3 molecules of water,
and the sodium ion is in positions À1 and B in coor-
dination with 2 atoms of oxygen and 5 molecules of
water. We will notice that cation bonding distances
for sodium are 0.258 nm for site A1 and 0.267 nm for
site B. The cation bonding distances for potassium
is 0.31 (2 bonds), 0.297 (2 bonds), 0.316 (2 bonds)
for site A1. The stronger connection of potassium
ions with atoms of a skeleton clinoptilolite also causes
lower di�usion mobility of potassium (see Fig.4).
Di�usion mobility of manganese (the ionic radius
of 0.0395 nm) a little more than for potassium. The
manganese is bound with only 2 atoms of oxygen
(A3-site) in a skeleton clinoptilolite. However, as a
result of small ionic radius manganese is bound to
6 molecules of water and with strong enough bonds
[13]. The cation-water distance for Mn6+ is only
0.22 nm. One can propose what the hydration com-
plex [Mn(H2O)6]
2+ di�uses as the whole.
Di�usion mobility of calcium (the ionic radius of
0.114 nm) a little smaller than for sodium. Calcium
bonds to three framework oxygen atoms and �ve wa-
ter molecules in the B-channel realize in clinoptilolite.
It is known that in a structure mutual substitution
between Ca and Na takes place, the Na polyhedra
tend to be larger than Ca polyhedra. With prolonged
leaching, the di�usion coe�cient of calcium decreases
substantially, which is possibly due to competition
with sodium ions for locations in the crystal lattice
of clinoptilolite.
Fig.5. Polyhedral model of a portion of the heulan-
dite structure projected parallel to the c-axis with
squares representing the most important extra-
framework sites. In addition, the prominent sym-
metry elements for space group C2/m are shown:
small circles=centre of inversion, heavy horizon-
tal lines=traces of mirror planes, double-barbed ar-
rows=twofold axes [13]
The di�usion of neutral radon in clinoptilolite is
carried out by the Knudsen mechanism. Therefore,
the di�usion coe�cient of radon in clinoptilolite is
more by 8-9 orders of magnitude with respect to other
ions.
4. CONCLUSIONS
1. The sums of the ratio of di�usion coe�cients
of sodium concerning caesium and strontium are in
antagonistic dependence on the caesium and stron-
tium content in a matrix on the basis of magnesium
potassium phosphate hexahydrate. The more of the
strontium content correspond to the more of the di�u-
sion coe�cient of caesium in a matrix on the basis of
magnesium potassium phosphate hexahydrate. The
more of the caesium content correspond to the more
di�usion coe�cient of strontium in ceramics.
2. It is established that the di�usion process in
the magnesium potassium phosphate hexahydrate is
caused by the transition of ions from the site posi-
tions of the regular lattice to the interstices, that is,
by the Frenkel mechanism.
3. The di�usion of gallium in magnesium potas-
sium phosphate hexahydrate is realized by the Shot-
tky mechanism.
4. The di�usion of cations in clinoptilolite is re-
alized by the interstitial mechanism and is depended
from ion positions in a crystal lattice of clinoptilolite.
References
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43
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ÈÎÍÍÛÉ ÎÁÌÅÍ Â ÔÎÒÎÀÊÒÈÂÈÐÎÂÀÍÍÛÕ ÍÅÎÐÃÀÍÈ×ÅÑÊÈÕ
ÂÅÙÅÑÒÂÀÕ
Í.Ï.Äèêèé, A.Í.Äîâáíÿ, Þ.Â.Ëÿøêî, Ä.Â.Ìåäâåäåâ, Å.Ï.Ìåäâåäåâà,
Þ.Ã.Ïàðõîìåíêî, Â.Ë.Óâàðîâ, È.Ä.Ôåäîðåö
Ïðîàíàëèçèðîâàíî âëèÿíèå ìîíîâàëåíòíûõ è äâóõâàëåíòíûõ ïðèìåñåé íà äèôôóçèîííóþ ïîäâèæ-
íîñòü íàòðèÿ, öåçèÿ è ñòðîíöèÿ â ãåêñàãèäðàòå ôîñôàòà êàëèÿ ìàãíèÿ. Îïðåäåëåíî, ÷òî îòíîøåíèÿ
êîýôôèöèåíòîâ äèôôóçèè íàòðèÿ îòíîñèòåëüíî öåçèÿ è ñòðîíöèÿ íàõîäÿòñÿ â àíòàãîíèñòè÷åñêîé çà-
âèñèìîñòè îò ñîäåðæàíèÿ öåçèÿ è ñòðîíöèÿ â ìàòðèöàõ íà îñíîâå ãåêñàãèäðàòà ôîñôàòà êàëèÿ ìàã-
íèÿ. Óñòàíîâëåíî, ÷òî äèôôóçèîííûé ïðîöåññ â ãåêñàãèäðàòå ôîñôàòà ìàãíèÿ îáóñëîâëåí ìåõàíèçìîì
Ôðåíêåëÿ. Èçó÷åíî âëèÿíèå äèôôóçèè ïðèìåñíûõ ýëåìåíòîâ â çàâèñèìîñòè îò èîííîãî ðàäèóñà è çà-
íèìàåìîé ïîçèöèè â êðèñòàëëè÷åñêîé ðåøåòêå êëèíîïòèëîëèòà.
IÎÍÍÈÉ ÎÁÌIÍ Ó ÔÎÒÎÀÊÒÈÂÎÂÀÍÈÕ ÍÅÎÐÃÀÍI×ÍÈÕ ÐÅ×ÎÂÈÍÀÕ
Ì.Ï.Äèêèé, A.Ì.Äîâáíÿ, Þ.Â.Ëÿøêî, Ä.Â.Ìåäâåä¹â, Î.Ï.Ìåäâåä¹âà,
Þ.Ã.Ïàðõîìåíêî, Â.Ë.Óâàðîâ, I.Ä.Ôåäîðåöü
Ïðîàíàëiçîâàíî âïëèâ ìîíîâàëåíòíèõ i äâîâàëåíòíèõ äîìiøîê íà äèôóçiéíó ðóõëèâiñòü íàòðiþ, öåçiþ
i ñòðîíöiþ â ãåêñàãiäðàòi ôîñôàòó êàëiþ ìàãíiþ. Âèçíà÷åíî, ùî âiäíîøåííÿ êîåôiöi¹íòiâ äèôóçi¨ íà-
òðiþ ùîäî öåçiþ i ñòðîíöiþ çíàõîäÿòüñÿ â àíòàãîíiñòè÷íié çàëåæíîñòi âiä âìiñòó öåçiþ i ñòðîíöiþ â
ìàòðèöÿõ íà îñíîâi ãåêñàãiäðàòi ôîñôàòó êàëiþ ìàãíiþ. Âñòàíîâëåíî, ùî äèôóçiéíèé ïðîöåñ ó ãåêñà-
ãiäðàòi ôîñôàòó êàëiþ ìàãíiþ îáóìîâëåíèé ìåõàíiçìîì Ôðåíêåëÿ. Âèâ÷åíî âïëèâ äèôóçi¨ äîìiøêîâèõ
åëåìåíòiâ â çàëåæíîñòi âiä iîííîãî ðàäióñà i çàéìàíî¨ ïîçèöi¨ â êðèñòàëi÷íié ðåøiòöi êëiíîïòiëîëiòà.
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