Journal of Crystallization Process and Technology, 2013, 3, 156-162
http://dx.doi.org/10.4236/jcpt.2013.34024 Published Online October 2013 (http://www.scirp.org/journal/jcpt)
Neutron Diffraction Study of Self-Curing and
Self-Crystallization Phenomena of Low-Temperature
Dehydrogenating Products of Powder Crystals of
Rare-Earth Metals Trihydroxides
Khidirov Irisali
Institute of Nuclear Physics of Uzbekistan, Tashkent, Uzbekistan.
Received April 2nd, 2013; revised May 2nd, 2013; accepted May 9th, 2013
Copyright © 2013 Khidirov Irisali. This is an open access article distributed under the Creative Commons Attribution License, which
permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
The phenomenon of hydrogen thermoemission out of a crystal lattice of powder rare-earth metals trihydrooxides
R(OH)3 (R is La, Pr, Nd) was found. The hydrogen thermoemission out of a crystal lattice is partial or full removal of
hydrogen out of the crystal lattice of powder hydrogen-containing crystal without change of symmetry of such crystal at
continuous evacuation of high vacuum at evacuation temperature of Тev. which is lower than recrystallization Тrecrys. or
disintegration (Tdisinteg.) temperature of this crystal: Тev. < Тrecrys. < Tdisineg.. By neutron diffraction it is found that low-
temperature (Тevacuation = 400 - 420 K ) removal of hydrogen (by hydrogen thermoemission) out of a crystal lattice of
trihydrooxide R(OH)3 under continuous high vacuum evacuating makes possible to obtain metastable “trioxide” R[O]3.
Existence of such substance contradicts to the valence law (oxygen is bivalent and Pr is trivalent in hydroxides). Such
“trioxide” has a superfluous negative charge: R3+O6−. So they aspire to “capture” three more protons (hydrogen ions)
from a water molecules. Obviously, this substance can be stable at low temperatures and in the mediums, which are not
containing hydrogen. In the air at room temperature this substance, most likely, interacting with water molecules,
gradually again turns into trihydroxide R(OH)3, compensating the superfluous negative charge by three hydrogen atoms.
From this it follows that substance R[O3] can simultaneously be an absorber of hydrogen and generator of oxygen at
atmospheric conditions and in any mediums which contains water molecules, without any prior processing like heating
or high pressure. Thus, the obtained material, without any prior processing like heating or high pressure, can simulta-
neously be oxygen generator and hydrogen accumulator in any mediums characteristic of R[O3] to transform into stable
form R(OH)3 by selective bonding of hydrogen from the hydrogen-containing environment allowing implication of
Pr[O3] as the hydrogen selective absorber. Separation (by low-temperature removal) of hydrogen out of R(OH)3 lattice
can again lead to restoration of its capabilities to be a simultaneous hydrogen accumulator and oxygen generator in a
medium containing water molecules.
Keywords: Hydrogen Termoemission; Rare-Earth Metals Trihydrooxides; Neutron Diffraction; High Vacuum;
Continuous Evacuation; Metastable “Trioxide” R[O3]
1. Introduction
In the review work [1] a short report was given about the
obtaining of metastable powder crystals of rare earth
metal “trioxides” R[O3] (were R is La, Pr, Nd) of the ra-
dical type by hydrogen thermoemission with the broken
chemical bonds and not-coupled electrons. The hy-
drogen thermoemission out of a crystal lattice is partial
or full removal of hydrogen out of the crystal lattice of
powder hydrogen-containing crystal without change of
symmetry of such crystal at continuous evacuation of
high vacuum at evacuation temperature of Тev. which is
lower than recrystallization Тrecrys. or disintegration (Tdisinteg.)
temperatures of this crystal: Тev. < Трrecrys. < Tdisineg. [1].
Hydrogen atoms in a powder crystal lattice, having small
nuclear weight, low binding energy and high diffusion
rate, leave the lattice in continuously pumped-out high
vacuum at relatively low temperaturewhich is lower than
the temperatures of disintegration or recrystallisation.
The configuration concerning relatively heavy atoms

Neutron Diffraction Study of Self-Curing and Self-Crystallization Phenomena of
Low-Temperature Dehydrogenating Products of Powder Crystals of Rare-Earth Metals Trihydroxides
157
(earlier stabilized with hydrogen atoms) cannot change
because of their insufficient diffusion mobility at this
temperature. It is obvious that the metastable “triоxid”
R[O3] obtained by hydrogen thermoemission has broken
bonds, unpaired electrons and excessive negative charge
Rr3+[O3]6− [1]. It tends “trap” to three deficit protons (of
a hydrogen ion) at the first possibility. This substance is
stable only at relatively low temperature and in the me-
dium free of hydrogen. In the air at room temperature,
this substance, interacting with water molecules, gradu-
ally turns to trihyrdoxides R(ОH)3 again, compensating
excessive negative charge by means of three hydrogen
atoms, trapping them from atmospheric water molecules,
and releasing oxygen molecules. The aim of this work is
to do more detailed study of the hydrogen thermoemis-
sion out of crystal lattice of powder rare earth metal
(REM) trihydroxides R (OH)3, (R is La, Pr, Nd) and ki-
netics of self-curing and self-crystallisation of low-temp-
erature dehydrogenating products of REM trihydroxides
in atmospheric conditions at room temperature by neu-
tron diffraction.
2. Experiment Techniques
The studied samples were obtained as a result of oxida-
tion of the corresponding REM (La, Pr and Nd) having
99.95% purity in air at room temperature. The obtained
samples were low-dispersed powder and the X-ray
analysis showed that these samples contained only trihy-
droxides of La, Pr and Nd with UCl3—type hexagonal
structure described in the frame of P63/m space group.
Samples composition was determined by chemical ana-
lysis and by minimizing of the R-factors of structure
determination based on neutron diffraction patterns.
These results are consistent with the results of other
authors [2,3]. All of them have lattice parameters close
to each other, which are identical with values resulted
in [2,3].
Neutron diffraction experiment was carried out using
the neutron diffractometer mounted at a thermal column
of atomic reactor WWR-SM of the Institute of Nuclear
Physics of Uzbekistan AS (
 = 0.1085 nm). Calculation
of structural characteristics was carried out by Rietveld
full-profile method [4] using neutron diffraction data.
X-ray diffraction patterns were obtained using the X-ray
diffractometer DRON -3M (
 = 0.15418 nm). Dehydro-
genation of samples was carried in the SShVL-type vac-
uum furnace in continuously pumped high vacuum of not
more than 5.33  10−3 Pa.
3. Results and Discussion
The neutron diffraction pattern of the initial sample Pr
(OH)3 is represented in Figure 1(a).
Diffraction patterns of other REM trihydroxides were
similar to that of Pr(OH)3. Since according to [2] and
data of the present work, all REMs R(OH)3 trihydroox-
ides having UCl3-type hexagonal structure (space group
P63/m) with lattice parameters close to each other, further
in the text for an illustration we will use neutron diffrac-
tion pattern of one of them. The least R-factors on Bragg
maxima at calculation of the neutron diffraction pattern
by method of Ritveld were obtaining for the model in the
frame of P63/m space group. The difference of experi-
mental and calculated intensities of the neutron diffrac-
tion pattern of the Pr (OH)3 in the frame of P63/m space
group is also presented in Figure 1(a). The structural
characteristics of the R(OH)3 samples are given in Table
1. These results are quite in agreement with data of the
work [2,3]. The strong incoherent background which is
falling down with increase of Bragg angle (Figure 1(a)
and see relatively the horizontal dotted line) is typical for
the neutron diffraction patterns of R(OH)3. According to
[5], only hydrogen nucleus causes the strong incoherent
background strongly decreasing with growing Bragg
angle because of large amplitude of incoherent scattering
Figure 1. Neutron diffraction patterns of the praseodymium
trihydroxid Pr(OH)3 (a) and the “trioxide” Pr[O3]; (b) The
dots are the neutron diffraction pattern data. The solid line
is the calculated profile.  is the difference curve (experi-
mental minus calculated). Above diffraction maxima were
indicated calculated positions reflections hkl in the frame
space group P63/m.
Table 1. The structural characteristics of R (OH)3 samples.
Atom Position х y z
2R 2(d) 0.6666 0.3333 ¼
6O 6(k) 0.300  0.002 0.385  0.002¼
6H 6(k) 0.160  0.003 0.288  0.004¼

Neutron Diffraction Study of Self-Curing and Self-Crystallization Phenomena of
Low-Temperature Dehydrogenating Products of Powder Crystals of Rare-Earth Metals Trihydroxides
158
of neutrons. Evacuation of hydrogen from lattice R(OH)3
began from the room temperature with the step of 25 K
in continuously pumped out high vacuum in the vacuum
furnace. Exposure time for each temperature at first was
24 h. At dehydrogenating of the REM trihydroxides in
the working volume of the furnace was provided at con-
tinuously pumped out to achieve the vacuum of not more
than 5.33  10−3 Pa. After dehydrogenating at every
temperature a neutron diffraction pattern was recorded
and hydrogen quantity in samples was examined by de-
cline of incoherent background caused by incoherent
neutron scattering on hydrogen nuclei. The hydrogen
content was also estimating by the analysis of the ex-
perimental and calculated neutron patterns intensities by
Ritveld method (on minimization of the R-factors). Fi-
nally, after continuous vacuum evacuation of R(OH)3 at
temperatures of 400 - 420 K during not less than 16 h
(Figure 1(b)) in the neutron diffraction pattern of the
samples did not contain a incoherent background which
was falling down with increase of Bragg angle (see rela-
tively to the horizontal dashed line at Figure 1(b)). It
was first sign of absence of hydrogen in crystals. But
previous diffraction patterns corresponding to the P63/m
space group observed in neutron diffraction patterns of
initial R(OH)3 remained, but their relation had changed.
Calculation of the neutron diffraction patterns of the
samples after dehydrogenation at temperatures of 400 -
420 K by the Ritveld method of the full profile analysis
shows that the sample does not contain hydrogen, but
crystal structures remains (Figure 1(b)). Essential reduc-
tion of the neutron diffraction intensity after dehydroge-
nation is the reason for, first of all, absence of hydrogen
atoms in a lattice; secondly, smaller total quantity of de-
hydrogenation samples. The latter is connected to the fact
that for acceleration of the process of hydrogen removal
from the R(OH)3 powders three times less quantity of
samples is taken than for initial R(OH)3 powders. After
hydrogen removal, one can observe widening of half-
width and distortion of diffraction peaks form, which is
caused by pronounced deformations in crystal lattice
after hydrogen removal. The best agreement between ex-
perimental and calculated intensities of neutron diffrac-
tion reflections (Figure 1(b)) and minimal errors in struc-
ture determination (R) can be obtained only assumed that
these crystal substances are “trioxides” having the che-
mical composition without hydrogen: R[O3]. It is worth
of mentioning that the temperature of hydrogen evacua-
tion out of lattice for all R(OH)3 trihydroxides within
errors in temperature determination (Т = 12 K) is al-
most the same. This can be explained by the fact that
REM metals La, Pr and Nd have similar valence electron
shells and does not differ in sizes and masses of atoms,
whereas all R(OH)3 trihydrooxides have isomorphic
structure. The results of calculations of the substance
Pr[O]3 neutron diffraction pattern in the frame P63/m
space group are presented in Table 2.
On should notice large errors in determination of the
lattice parameters and large value of the RBr.. It is appar-
ently caused by distortion of diffraction peaks’ forms due
to strong statistical lattice deformations appearing after
hydrogen removal. Formation of such a compound in the
R-O systems contradicts to the valence conservation
principle. Oxygen is double-valence, and REM can be
either three- or four-valent. But all of them in R(OH)3 are
three-valent. Apparently, it is necessary to assume that
“trioxides” R[O3] have broken bonds and unpaired elec-
trons, likewise that of radicals, that is they have exces-
sive negative charge: R3+[O3]6−. Apparently, therefore
R3+[O3]6− have dead color and a sharp specific smell.
Hydrogen thermoemission in powder crystals of rare
earth metal trihydroxides R(OH)3 can be explained as
relief of potential wells in crystals (Figure 2). Heavy
atoms and hydrogen atoms have different initial wells.
Hence to overcome the potential barrier less energy is
required for hydrogen compared to heavier atoms. These
substances are stable only at relatively low-temperatures
and in media free of hydrogen. Indeed, annealing of R[O3]
or vacuum evacuation of hydrogen out of lattice of
R(OH)3 at temperature 420 K longer than 24 hours leads
to its amorphisation, which is pointed by lack of selective
diffraction reflections in neutron patterns and formation
of small diffuse reflection at Bragg angles of 2θ = 28 - 38
degrees (Figure 3). Similar phenomenon takes place
Table 2. Structural characteristics and R-factors of the
Pr[O3] “trioxide” in the model of space group P63/m.
Coordinates
АtоmNumber
of atomsPosition
x y z
Pr 2 2(d) 2/3 1/3 1/4
O 6 6(k) 0.376 ± 0.002 0.461 ± 0.0021/4
a = 0.658 ± 0.018 nm; с = 0.381 ± 0.006 nm;
Rp = 1.4%; Rwp =1.8%; RBr = 9.4%
Figure 2. The relief of potential wells in rare earth metal
trihydroxides R(OH)3.

Neutron Diffraction Study of Self-Curing and Self-Crystallization Phenomena of
Low-Temperature Dehydrogenating Products of Powder Crystals of Rare-Earth Metals Trihydroxides
159
Figure 3. Neutron diffraction pattern of the amorphous
Pr[O3].
at even slight increase of temperature up to 420 K. The
soaking of R(OH)3 trihydroxides or R[O3] “oxides” in
continuously pumped out vacuum at temperature Т 
470 K leads to escape both atoms of hydrogen and par-
tially atoms of oxygen. At the same time recrystalliza-
tion occurs and cubic oxide phases of corresponding
REM is formed (PrO2−x phase instead of Pr(OH)3 or
La2O3 phase instead of La(OH)3 are formed (Figure 4).
The diffraction patterns of the crystallines R[O3] samples
after exposition in atmosphere at temperatures 285 - 290
K (the temperature in the reactor hall in winter) within 30
days are both and quantitatively become identical to the
corresponding neutron diffraction patterns for the R(OH)3.
Hence, one can conclude that in atmosphere the “triox-
ides” R[O3] “self-cures” until complete restoration of the
REM trihydrooxides R(OH)3. Obviously, the reaction rate
depends on temperature.
The self-curing of the “trioxides” R[O3] can be most
likely explained as follows. The “trioxides” R[O3] due to
its valence instability “tends” to trap three more protons.
This can be accomplished by trapping in lattice of three
hydrogen ions at first instance. Therefore, metastable rare-
each metal “trioxides” in atmosphere, apparently, interact
with water molecules, and retransform step by step back
in the trihydrooxide R(OH)3, by compensating the exces-
sive charge by three hydrogen atoms. This is demon-
strated by the neutron diffraction analysis calculations of
the product R[O3], taken in 30 days after obtaining of
neutron diffraction patterns and by repeated formation of
incoherent background on the neutron diffraction pat-
terns. Since the hydrogen concentration on Earth’s sur-
face is rather low, one can assume that R[O]3 captures
hydrogen, mainly from, water vapors in the air, leaving
oxygen molecules free:


 
3
2
2
3
6
3
4ROpowdermetastable crystal6HO
4ROHpowderstable crystal3O.



If so, hence, “trioxide” R [O3] in atmospheric condi-
tions can be simultaneously a hydrogen absorber and the
oxygen generator. Separation (by low-temperature re-
moval) of hydrogen out of R(OH)3 lattice can again lead
to restoration of its capabilities to be a simultaneous hy-
drogen accumulator and oxygen generator in a medium
containing water molecules. The cycle described above
can be accomplished many times. It is shown in Figure
5.
It is useful to compare transformation rates of the
“trioxides” R[O]3 and the monoxides ROOH (by the way,
obtained by dehydrogenation of the compositions
R(OH)3 in air at the temperature of T ~ 670 K [6]). The
hydroxides ROOH even at short-term contact to air in
atmospheric transform very quickly to corresponding R
(OH)3 trihydrooxides, that is caused by capture in air of
water molecules by the monoxides ROOH without spli-
ting into atoms [6]. It is possible to assume, that the “tri-
oxides” R[O3] can “trap” hydrogen not only from water
vapour, but also from other gaseous environment, having
hydrogen partial pressure. Advantage of the “trioxides”
R[O3] in comparison to other hydrogen-containing mate-
rials (for example, the titanium or intermetallic com-
pounds) is that it absorbs hydrogen at small partial pres-
sure and low temperature without an energy expense
from outside. If the trihydroxide R(OH)3 to sustain at
continuously pumped out vacuum at temerature of Т 
420 K less, than 16 h then part of hydrogen in a lattice
remains, which can be observed by the remained inco-
herent background in the neutron diffraction patterns.
The analysis of the neutron pattern shows, that in these
Figure 4. Neutron diffraction pattern of the PrO2−x (cubic
phase, space group Fm3m). Above diffraction maxima were
indicated Miller indexes hkl in the frame of space group
Fm3m.
Figure 5. The scheme of the cycle of R[O3] production from
R(OH)3 at continuously pumped high vacuum and repeated
formation of R(OH)3 from “trioxide” R[O3] by self-curing
in atmospheric conditions.

Neutron Diffraction Study of Self-Curing and Self-Crystallization Phenomena of
Low-Temperature Dehydrogenating Products of Powder Crystals of Rare-Earth Metals Trihydroxides
160
conditions the strongly nonstochiometric hydroxides
R[O3H1] are formed. For example, the structural charac-
teristics and R-factors of determination of the structure
for the substance Pr [O3H1] are given in Table 3. The
soaking of these hydroxides nonstochiometric by hydro-
gen in atomspheric conditions for several days also leads
to their “self-curing”, that is to restoration of the com-
plete trihydrooxides R(OH)3. The experiments revealed
that amorphous R[O3] in atmosphere crystallize sponta-
neously and transform into trihydrooxides of corre-
sponding rare earth metals during 1 - 1.5 months at the
temperature of the nuclear reactor hall in winter (285 -
290 K).
It was interesting to study the kinetics of this process.
We therefore periodically generated the neutron diffract-
tion pattern of amorphous La[O3]. During the measure-
ments the sample was located continuously in the vana-
dium cylinder with diameter 6 mm and opened cap. Fig-
ure 6 shows some peculiar neutron diffraction patterns
taken within 50 days. After evacuation of hydrogen out
of lattice the La (OH)3 at temperature of 420 K for more
than 24 h selective reflections disappear in neutron dif-
fraction pattern and appear as both weak, and rather
weak diffuse reflections. In the next 10 days weak dif-
fraction maxima appear at Bragg angles 2θ = 15˚ and 19˚,
and intensity of diffuse reflections essentially grows (at
Bragg angles 2θ = 24˚ - 39˚. After 15 days, weak selec-
tive reflections are formed on the diffuse maxima (Fig-
ure 6). The indicating shows that positions of these
peaks correspond to the face-centered cubic oxide phase
of La2O3 (space group Fm3m). Hence, at the first stage in
the amorphous phase the germs of the cubic oxide phase
of La2O3 are formed. Further intensity of the reflections
of the La2O3 oxide phase increases and diffuse reflection
intensity decreases demonstrating that the formed oxide
phase grows instead of the amorphous phase.
It is interesting to observe that on the 5th day after nu-
cleation of the oxide phase, it disappear from the neutron
diffraction pattern and one can observe some small dif-
fraction maxima of the trihydroxide La(OH)3 (Figure 6).
Indeed, according to [2,7], REM oxides R2O3, by ab-
Таble 3. The structural characteristics and R-factors for the
strongly nonstochiometric hydroxides P[O3H1] in the frame
of P63/m space group.
Atom Number
of atoms Position X у z
Pr 2 2(d) 2/3 1/3 ¼
O 6 6(k) 0.36 ± 0.01 0.44 ± 0.01 ¼
H 1 6(k) 0.16 ± 0.09 0.40 ± 0.09 ¼
a = 0.660 ± 0.018 nm; с = 0.382 ± 0.02 nm;
Rp = 0.60%; Rwp = 0.81%; RBr = 5.6%
Figure 6. Neutron diffraction patterns of the amorphous
La[O3] taken during spontaneous crystallization and its
repeated transformation into La (OH)3 during various
times: 1-amorphous La[O3]; after its exposure in atmos-
pheric conditions during times t.
sorbing a moisture from air, turn into to REM trihydrox-
ides R(OH)3. In what follows the diffraction maxima of
the trihydroxide phase R(OH)3 increase, and the diffuse
reflexions decrease and finally disappear (Figure 6). In
the beginning the diffraction reflections of the trihy-
drooxide La(OH)3 are strongly distorted, but finally they
acquire ideal Gaussian form. Thus, duration of process of
spontaneous crystallization and complete transformation
of the amorphous La[O3] into the crystalline trihydrox-

Neutron Diffraction Study of Self-Curing and Self-Crystallization Phenomena of
Low-Temperature Dehydrogenating Products of Powder Crystals of Rare-Earth Metals Trihydroxides
161
ide La(OH)3 in atmosphere at temperatures 285 - 290 K
is approximately 30 days. Certainly, the observed reac-
tion rate depends on air temperature and humidity. To
find out, how strong is such dependence on temperature
we have sustained amorphous substance La[O3] in air at
temperature 340 K within 2 hours. The neutron diffrac-
tion measurement after this endurance shows that the
amorphous substance has already turned in badly gener-
ated La (OH)3 trihydroxide.
The author expresses sincere gratitude to Dr. Muslim
Fazilov for the technical help.
4. Conclusions
Similar to being observed in powder interstitial solid
solutions of the Ti-N-H, Zr-N-H and Ti-C-H systems
[1,8-10], the hydrogen thermoemission phenomenon out
of the crystal lattice of the chemical compounds of the
rare-earth metal trihydroxides R(OH)3 is found. The
hydrogen thermoemission out of a crystal lattice is partial
or full removal of hydrogen out of a crystal lattice of a
powder hydrogen-containing crystal without change of
symmetry of a crystal at evacuation in continuously pumped-
out high vacuum at evacuation temperature Тev. lower
than recrystallization Тrecrys. or disintegration (Tdisinteg.)
temperature of this crystal: Тev. < Трrecrys. < Tdisineg.. The
phenomenon of hydrogen thermoemission in crystals can
be observed only in powder samples due to simplifica-
tion of hydrogen degasification, which has left a potential
hole of a crystal lattice. As in the present stage of devel-
opment materials technology, it is even possible to deal
with nanocrystals and the hydrogen thermoemission can
be used for obtaining new crystals in micro- and nano-
sizes.
In the work, according to the neutron diffraction
structural analysis, metastable powder crystal rare earth
“trioxides” R3+[O3]6− of radical type are received by hy-
drogen thermoemission at temperature of 400 - 420 K
which are stable only at relatively low temperature which
is lower than Т  400 - 420 K and in hydrogen-free en-
vironment. The substance R3+[O3]6 possesses “self-cur-
ing” property grasping deficient hydrogen in environ-
ment containing hydrogen, and in atmospheric condi-
tions, most likely, grasping hydrogen and releasing О2
from water molecules. Hence, the substance R[O3] si-
multaneously be hydrogen accumulator and oxygen gen-
erator in atmospheric conditions or in any environment
containing water molecules without preliminary condi-
tions (without heating and high pressure creation). The
expenditure (by low-temperature removal) of hydrogen
from R(OH)3 again leads to restoration of its property to
simultaneously be the generator of oxygen and the hy-
drogen accumulator in the environment containing water
molecules. The cycle described above can be accom-
plished many times. The given cycle is outlined.
For powder crystals of rare earth metal trihydroxides
three characteristic temperatures of hydrogen extraction
out of their crystal lattice in continuously pumped-out
high vacuum are determined:
1) The temperature of practically complete hydrogen
evacuation out of a lattice without change in symmetry of
a crystal—Tev (400 - 420 K), at which a crystal structure
does not change, but is significantly deformed;
2) The amorphisation temperature—Тamorp (450 K) at
which the selective diffraction reflections disappear and
diffuse reflections appear in the neutron diffraction pat-
tern;
3) The recrystallisation temperature—Тrecr. ( 480 K)
at which cubic oxides phases corresponding to RO2−x or
La2O3 form instead of the trihydroxides Pr(OH)3 and
La(OH)3.
Strongly nonstochiometric rare earth metal hydroxides
R[O3H1] are received from R(OH)3 by hydrogen ther-
moemission method and by that it is shown, that concen-
tration of hydrogen in rare earth metal trihydroxides can
be varied in a wide range up to full extraction of hydro-
gen out of a crystal lattice which possesses the property
of self-curing in hydrogen-containing environment.
The interesting phenomenon consisting in spontaneous
crystallisation of the amorphous substances R[O3] and its
return transformation into the three hydroxides R(OH)3 is
revealed in normal atmospheric conditions by selective
absorption of a hydrogen from a water molecule or from
a gaseous environment, having partial pressure of hy-
drogen. Duration of the observed process is about 35 days in
atmospheric conditions at temperature of 285 - 290 K.
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