The plasma evaporation-sputtering method was applied to make composite materials of the Mg-Ti system.
The ion-implanted deuterium desorption temperature variations as a function of the component concentration
were studied. It has been established that, by introducing titanium into magnesium, the deuterium
desorption temperature can be appreciably decreased (to 400-450 K) in comparison with the case of
deuterium desorption from magnesium ( 800 K). A step-like shape of the curve of deuterium desorption
temperature evidences on the presence of two different structure states of the Mg-Ti system depending on
the ratio of components. The deuterium temperature decrease can be caused by filamentary inclusions of
insoluble component (titanium) atoms formed in the process of composite making and annealing, providing
the deuterium diffusion from the sample at a lower temperature (channels for deuterium diffusion through
the surface barrier). The deuterium desorption data obtained on the example of Mg-Ti, Mg-V and Mg-Zr
composites provide support for further research into hydrogen storage materials containing low-soluble
chemical elements in the alloy component.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3550

Galitskiy, O.G.

Kulish, V.G.

Kuprin, A.S.

Lomino, N.S.

Morozov, O.M.

Neklyudov, I.M.

Ovcharenko, V.D.

Progolaieva, V.O.

Zhurba, V.I.

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  
NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 2 No 4, 04NEA04 (4pp) (2013) 
 
 
2304-1862/2013/2(4)04NEA04 (4) 04NEA04-1  2013 Sumy State University 
Effects of Concentration Titanium on Threshold Character of Deuterium 
Desorption Temperature Range from Mg-based Composites  
 
O.M. Morozov*, V.G. Kulish, V.I. Zhurba, I.M. Neklyudov, V.O. Progolaieva, 
A.S. Кuprin, N.S. Lomino, V.D. Оvcharenko, O.G. Galitskiy2 
 
1National Science Center “Kharkov Institute of Physics & Technology”, 1, Akademicheskaya Str., Kharkov, Ukraine 
2 G. S. Skovoroda National Pedagogical University at Kharkov, 29, Artema Str., 61029 Kharkov, Ukraine 
 
(Received 20 May 2013; published online 31 August 2013) 
 
The plasma evaporation-sputtering method was applied to make composite materials of the Mg-Ti sys-
tem. The ion-implanted deuterium desorption temperature variations as a function of the component con-
centration were studied. It has been established that, by introducing titanium into magnesium, the deuter-
ium desorption temperature can be appreciably decreased (to 400-450 K) in comparison with the case of 
deuterium desorption from magnesium ( 800 K). A step-like shape of the curve of deuterium desorption 
temperature evidences on the presence of two different structure states of the Mg-Ti system depending on 
the ratio of components. The deuterium temperature decrease can be caused by filamentary inclusions of 
insoluble component (titanium) atoms formed in the process of composite making and annealing, providing 
the deuterium diffusion from the sample at a lower temperature (channels for deuterium diffusion through 
the surface barrier). The deuterium desorption data obtained on the example of Mg-Ti, Mg-V and Mg-Zr 
composites provide support for further research into hydrogen storage materials containing low-soluble 
chemical elements in the alloy component.  
 
Keywords: Nanostructured Composites, Deuterium, Thermal Desorption, Implantation, Hydrogen Storage. 
 
 PACS numbers: 81.07.Bc, 65.80. + n, 29.27.Ac 
 
                                                 
* morozov@kipt.kharkov.ua 
1. INTRODUCTION 
 
Magnesium-based alloys are promising in the view 
of present-day requirements to the metal-hydride hy-
drogen storage systems. Behavior of hydrogen in the 
magnesium-based alloys is of scientific and applied 
interest that is confirmed by many publications [1-17]. 
However, the use of such alloys presents some difficul-
ties because of the high hydrogen desorption tempera-
ture (550-600 K).  
Particular attention is given to materials in a nano-
crystalline state. An exclusive position of nanocrystal-
line materials as hydrogen storage materials is deter-
mined by their unique structural properties that can, 
probably, provide a high sorption capacitance and po-
tentially high concentrations for hydrogen storage. 
Therefore it is reasonable that reports about investiga-
tions on the hydrogen behavior in the nanocrystalline 
materials become more and more frequent in the litera-
ture [15-17]. One of the methods for obtaining materi-
als in the nanocrystalline state is introduction of 
nanoformative elements. We believe that they are 
chemical elements with a low solubility or elements not 
interacting with components of composites being com-
posed. The literature data confirm that investigations 
in this direction are promising [5, 6, 15]. 
The purpose of this work is to make Mg-Ti compo-
sites using the method of atom-by-atom mixing of com-
ponents and to study mechanisms of hydrogen storage 
and thermoactivated release from the samples obtained 
depending on the component concentration. Note, that, 
practically, Mg and Ti are not alloyable, therefore, in 
the system the liquid-and-solid phase immiscibility is 
observed [18]. 
 
2. MATERIALS AND METHODS 
 
In our work the Mg-Ti composites with a different 
concentration of magnesium and titanium were made 
by plasma evaporation-sputtering of composites com-
ponents (Fig. 1). Using an atom-by-atom deposition of 
components it is possible to obtain composites with a 
high concentration of insoluble components. 
 
 
 
Fig. 1 – Schematic representation of the experimental facility 
for making  the  samples by  plasma  evaporation-sputterings: 
1 – cathodes of metals to be sputtered – Mg and Ti; 2 – sample 
holder; 3 – gas bottles; 4 – pumps; 5 – pressure meters 
 
Thus, the composites with a wide range of the ratios 
of insoluble components were obtained [16]. A compo-
site was deposited on the molybdenum foils (0.2 mm 
thickness, 10 mm width, 250 mm length) placed be-
tween the cathode assemblies in the facility. In parallel 
 O.M. MOROZOV, V.G. KULISH, V.I. ZHURBA, ET AL. PROC. NAP 2, 04NEA04 (2013) 
 
 
04NEA04-2 
with the molybdenum foils there were arranged the 
copper plates (10 10 mm2) as standards for determin-
ing the thickness of obtained samples by the gravimet-
ric method and composite component concentrations – 
by the X -ray fluorescent method. 
Figure 2 represents the magnesium and titanium 
concentration in the Mg–Ti samples, measured by the 
method of X-ray fluorescence analysis, as a function of 
the distance between the magnesium and titanium 
cathodes. 
 
 
 
Fig. 2 – Magnesium and titanium concentration in the Mg-Ti 
composite samples versus the distance between the 
magnesium and titanium cathodes 
 
Deuterium introduction into the samples was per-
formed by the ion implantation method. Deuterium 
desorption temperature ranges and deuterium storage 
levels were determined by the thermal desorption spec-
troscopy. Deuterium introduction into the samples was 
performed by the ion implantation method. Deuterium 
desorption temperature ranges and deuterium storage 
levels were determined by the thermal desorption spec-
troscopy.  
In experiments a hydrogen isotope (deuterium) was 
used to decrease the influence of the background 
hydrogen contained in samples and target chambers. 
The samples were mounted on foils-heaters made of 
stainless steel Ch18Ni10Ti (5 45 0.3 mm3). The 
temperature was measured with a chromel-alumel 
thermocouple fastened to the heater. 
 
3. RESULTS AND DISCUSSION 
 
The most characteristic spectra of ion-implanted 
deuterium thermal desorption from the Mg-Ti 
composites are shown in Fig. 3. The figure 
demonstrates the thermal desorption spectrum (TDS) 
evolution from the composite composition and the 
implanted deuterium dose, as well as, the 
corresponding temperatures of maximum peaks in the 
deuterium TDS against the magnesium concentration 
in the samples under study. 
A low magnesium concentration and, consequently, 
a high titanium concentration in the composite are 
revealed in the deuterium TDS as a single peak with a 
maximum temperature at 800-950 K depending on the 
implanted deuterium dose and composite composition 
(Fig. 3 a, b). A single-peak character of the deuterium 
TDS, observed for magnesium concentration values 
ranging from 1 to 30 at. , evidences on the 
homogeneity of composite structural state in this 
range. As the magnesium concentration in the 
composites increases to the Mg30Ti70 composition, the 
maximum peak temperature in the deuterium TDS 
rises to the temperature of 950 K. So, the magnesium 
influence on the temperature range of deuterium 
trapping is increasing (see Fig. 3b).  
The temperature range of deuterium desorption 
from the  magnesium- titanium  composites,  having   
ahigh titanium content, on the temperature scale is 
within the region of the deuterium solid solution in α-
titanium. Besides, for Mg30-хTi70+x  composites the peak 
maximum temperature displaces with implantation 
dose increasing in the deuterium TDS towards the 
temperature decrease that has been earlier observed 
for the titanium samples located at the substrate [19]. 
With a dose of 2 1018 D/cm2 there is in the 
deuterium TDS of Mg30-хTi70+x composites an additional 
low-intensity low-temperature slightly sloped peak 
with a centre of gravity at 300-400 К. This indicates 
on the fact that the process of deuterium solid-solution 
phase state formation in the composite has finished 
and the process of hydride formation has started. 
A step-like form of the maximum temperature curve 
obtained for the thermoactivated deuterium release 
from composites as a function of the magnesium 
concentration evidences on the existence of two 
different structural states of the system depending on 
the ratio of components. At the same time, in each of 
the states being observed a main role is performed by 
one of the components – magnesium or titanium. 
Analysis of the shapes of curves shown in Fig. 4, illustrating the 
change in the concentration of deuterium desorbed from  
Mg30Ti70 (part I) and Mg83.5Ti16.5  (part II) composites, has 
shown an appreciable difference in the dependence on the ratio 
of composite components. In the concentration region where 
titanium (Mg30-хTi70+х composites) plays a prevailing role, one 
can see a linear growth of the amount of deuterium trapped due 
to the implantation dose increase. The foregoing permits to 
draw a conclusion about a high mobility of deuterium by 
diffusion in such composites and deuterium release from the 
implantation region and propagation throughout the sample 
volume.  A similar effect was observed for palladium at a 
temperature of deuterium implantation of 100 K [20]. 
In the case of Mg40+хTi60-х composites the amount of 
trapped deuterium is decreasing beginning from the 
dose of ~1 1018 D/cm2 with a tendency towards the 
attainment of saturation when the implantation dose 
exceeds 2 1018 D/cm2. It means that in this composite 
the implanted deuterium has the low diffusion mobility 
and its accumulation takes place mainly in the 
implantation volume.  
The structure of deuterium TDS in the case of 
Mg40+хTiх composites strongly depends on the 
implanted deuterium dose. For the low implantation 
doses (3 1015 D/cm2) the spectrum has only one high-
temperature peak with the centre of gravity at 850-
900 K. The implanted deuterium dose increase is 
accompanied by the extension of the deuterium 
desorption temperature range towards the temperature 
decrease (Fig. 3d, curves 2 and 3). Beginning from the 
dose of 1 1017 D/cm2 there is observed a deuterium 
desorption region with a centre of gravity at 400 K.  
The intensity of this peak continues to grow up to the 
dose of 9 1017 D/сm2. As the implanted deuterium dose 
 EFFECTS OF CONCENTRATION TITANIUM ON THRESHOLD … PROC. NAP 2, 04NEA04 (2013) 
 
 
04NEA04-3 
goes on, the amount of trapped deuterium decreases 
(see Fig. 4, curve 2) and an additional low-temperature 
region of deuterium desorption with a centre of gravity 
at 300-330 K appears (Fig. 3d, curve 7). The low-
temperature intensity increases owing to the implanted 
deuterium and deuterium trapped before at a higher 
temperature. The changes observed in the deuterium 
TDS evidence on the structure transformation in the 
implantation layer. 
 
 
 
Fig. 3 – Deuterium desorption temperature versus the Mg-Ti composition ( ) for a deuterium dose of 1 1018 D/cm2 (Tirr. 100 K) 
and thermal desorption spectra of deuterium released from composites: (a) Mg06Ti94; (b) Mg30Ti70; (c) Mg41Ti59; (d) Mg66.5Ti33.5 
 
 
 
 
Fig. 4 – Amount of desorbed deuterium versus the implanted 
dose for the Mg30Ti70 (1- ) and Mg83.5Ti16.5 (2-  ) composites 
 
An additional low-temperature peak in TDS, which 
becomes prevailing with the implanted deuterium dose 
increasing and reaches the maximum desorption 
temperature of the main low-temperature peak 
300 K, arises due to the temperature decreasing 
during deuterium desorption from the Mg-Ti 
composites having the titanium concentration less than 
60 at. .The deuterium temperature decrease can be 
caused by filamentary inclusions of insoluble 
component atoms (titanium in our case) formed, in the 
process of composite making and annealing, which 
provide the deuterium diffusion from the sample at a 
lower temperature (channels for deuterium diffusion 
through the surface barrier). 
 
4. CONCLUSIONS 
 
The present paper shows that by introducing titanium 
into magnesium the deuterium desorption temperature 
can be significantly decreased (to 400-450 K) compared to 
desorption from the magnesium samples ( 800 K). 
A step-like shape of the maximum temperature curve 
of thermoactivated deuterium desorption as a function of 
the component concentration change evidences on the 
presence of two different structure states of the Mg-Ti 
system depending on the ratio of components. 
The deuterium temperature decrease can be caused by 
filamentary inclusions of insoluble component atoms, 
formed in the process of making and annealing, which 
provide the deuterium diffusion from the sample at a 
lower temperature (channels for deuterium diffusion 
through the surface barrier). 
The deuterium desorption data obtained using Mg-Ti, 
Mg-V [15] and Mg-Zr [16] composites provide support for 
further research into the hydrogen storage materials 
containing low-soluble chemical elements in the alloy 
components. 
 
 
 O.M. MOROZOV, V.G. KULISH, V.I. ZHURBA, ET AL. PROC. NAP 2, 04NEA04 (2013) 
 
 
04NEA04-4 
ACKNOWLEDGEMENT 
 
This study has been done with financial support to 
the program at the National Academy of Sciences of 
Ukraine “Hydrogen in the alternative energy and new 
technologies” (Project #27-13). 
 
REFERENCES 
 
1. J. Huot, D.B. Ravnsbæk, J. Zhang, F. Cuevas, 
M. Latroche, T.R. Jensen. Prog. Mater. Sci. 58, 30 (2013). 
2. K. Asano, H. Enoki, E. Akiba, J. Alloys Compd. 480, 558 
(2009). 
3. H. Shao, G. Xin, J. Zheng, X. Li, E. Akiba, Nano Energy 1, 
590 (2012). 
4. M. Anik, F. Karanfil, N. Kucukdeveci, Int. J. Hydrogen 
Energy 37, 299 (2012). 
5. O. Ershova, V. Dobrovolsky, Yu. Solonin, O. Khyzhun, 
A. Koval, J. Alloys Compd. 464, 212 (2008). 
6. S.X. Tao, P.H.L. Notten, R.A. van Santen and 
A.P.J. Jansen, Phys. Rev. 83B, 195403 (2011). 
7. C. Zlotea, F. Cuevasa, J. Andrieux, C. Ghimbeu, E. Leroy, 
E. Leonel, S. Sengmany, C. Vix-Guterl, R. Gadiou, 
T. Martens, M. Latroche. Nano Energy 2, 12 (2013). 
8. S.D. Vincent, J. Lang, J. Huot. J. Alloys Compd. 512, 290 
(2012). 
9. M. Anik, F. Karanfil, N. Kucukdeveci. Int. J. Hydrogen 
Energy, 37, 299 (2012). 
10. Y. He, Y. Liu and Y. Zhao, Nanotechnology 19, 465602 
(2008). 
11. P. Pei, X. Song, J. Liu, A. Song, P. Zhang, G. Chen, Int. J. 
Hydrogen Energy 37, 984 (2012). 
12. M.S. Park, A. Janotti, and C.G. Van de Walle, Phys. Rev. 
80B, 064102 (2009). 
13. L. Pasquini, M. Brighi, A. Montone, M.V. Antisari, 
B. Dam, V. Palmisano and E. Bonetti, IOP Conf. Series: 
Mat. Sci. Eng., 38, 012001 (2012). 
14. M.G. Shelyapina, D. Fruchart, S. Miraglia, and G. Girard, 
Phys. Solid State 53, 6 (2011). 
15. I.M. Neklyudov, O.M. Morozov, V.G. Kulish, V.I. Zhurba, 
A.G. Galitskiy, N.S. Lomino, A.S. Kuprin, 
V.D. Ovcharenko, E.N. Reshetnyak, IOP Conf. Ser.: Mater. 
Sci. Eng. 38, 012028 (2012) 
16. I.M. Neklyudov, O.M. Morozov, V.G. Kulish, V.I. Zhurba, 
N.S. Lomino, V.D. Оvcharenko and O.S. Кuprin, IOP Conf. 
Ser.: Mater. Sc.i Eng. 23 012028 (2011). 
17. R. Varin, T. Czujko, Z. Wronski, Nanomaterials for Solid 
State Hydrogen Storage (Springer: 2009). 
18. 1999 State diagrams of double metal systems vol 3-1 ed. 
N.P. Lyakishev (Moscow: Mashinostroyenie) [in Russian] 
19. I.M. Neklyudov, O.M. Morozov and V.G. Kulish Materi-
alovedenie 11, 45 (2000) [in Russian]. 
20. V.F. Rybalko, A.N. Morozov, I.M. Neklyudov, V.G. Kulish, 
Phys. Lett. 287A, 175 (2001). 
 
 


Effects of Concentration Titanium on Threshold Character of Deuterium Desorption Temperature Range from Mg-based Composites

Electronic Sumy State University Institutional Repository

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  NANOMATERIALS: APPLICATIONS AND PROPERTIES Vol. 2 No 4, 04NEA04 (4pp) (2013)   2304-1862/2013/2(4)04NEA04 (4) 04NEA04-1  2013 Sumy State University Effects of Concentration Titanium on Threshold Character of Deuterium Desorption Temperature Range from Mg-based Composites   O.M. Morozov*, V.G. Kulish, V.I. Zhurba, I.M. Neklyudov, V.O. Progolaieva, A.S. Кuprin, N.S. Lomino, V.D. Оvcharenko, O.G. Galitskiy2  1National Science Center “Kharkov Institute of Physics & Technology”, 1, Akademicheskaya Str., Kharkov, Ukraine 2 G. S. Skovoroda National Pedagogical University at Kharkov, 29, Artema Str., 61029 Kharkov, Ukraine  (Received 20 May 2013; published online 31 August 2013)  The plasma evaporation-sputtering method was applied to make composite materials of the Mg-Ti sys-tem. The ion-implanted deuterium desorption temperature variations as a function of the component con-centration were studied. It has been established that, by introducing titanium into magnesium, the deuter-ium desorption temperature can be appreciably decreased (to 400-450 K) in comparison with the case of deuterium desorption from magnesium ( 800 K). A step-like shape of the curve of deuterium desorption temperature evidences on the presence of two different structure states of the Mg-Ti system depending on the ratio of components. The deuterium temperature decrease can be caused by filamentary inclusions of insoluble component (titanium) atoms formed in the process of composite making and annealing, providing the deuterium diffusion from the sample at a lower temperature (channels for deuterium diffusion through the surface barrier). The deuterium desorption data obtained on the example of Mg-Ti, Mg-V and Mg-Zr composites provide support for further research into hydrogen storage materials containing low-soluble chemical elements in the alloy component.   Keywords: Nanostructured Composites, Deuterium, Thermal Desorption, Implantation, Hydrogen Storage.   PACS numbers: 81.07.Bc, 65.80. + n, 29.27.Ac                                                   * morozov@kipt.kharkov.ua 1. INTRODUCTION  Magnesium-based alloys are promising in the view of present-day requirements to the metal-hydride hy-drogen storage systems. Behavior of hydrogen in the magnesium-based alloys is of scientific and applied interest that is confirmed by many publications [1-17]. However, the use of such alloys presents some difficul-ties because of the high hydrogen desorption tempera-ture (550-600 K).  Particular attention is given to materials in a nano-crystalline state. An exclusive position of nanocrystal-line materials as hydrogen storage materials is deter-mined by their unique structural properties that can, probably, provide a high sorption capacitance and po-tentially high concentrations for hydrogen storage. Therefore it is reasonable that reports about investiga-tions on the hydrogen behavior in the nanocrystalline materials become more and more frequent in the litera-ture [15-17]. One of the methods for obtaining materi-als in the nanocrystalline state is introduction of nanoformative elements. We believe that they are chemical elements with a low solubility or elements not interacting with components of composites being com-posed. The literature data confirm that investigations in this direction are promising [5, 6, 15]. The purpose of this work is to make Mg-Ti compo-sites using the method of atom-by-atom mixing of com-ponents and to study mechanisms of hydrogen storage and thermoactivated release from the samples obtained depending on the component concentration. Note, that, practically, Mg and Ti are not alloyable, therefore, in the system the liquid-and-solid phase immiscibility is observed [18].  2. MATERIALS AND METHODS  In our work the Mg-Ti composites with a different concentration of magnesium and titanium were made by plasma evaporation-sputtering of composites com-ponents (Fig. 1). Using an atom-by-atom deposition of components it is possible to obtain composites with a high concentration of insoluble components.    Fig. 1 – Schematic representation of the experimental facility for making  the  samples by  plasma  evaporation-sputterings: 1 – cathodes of metals to be sputtered – Mg and Ti; 2 – sample holder; 3 – gas bottles; 4 – pumps; 5 – pressure meters  Thus, the composites with a wide range of the ratios of insoluble components were obtained [16]. A compo-site was deposited on the molybdenum foils (0.2 mm thickness, 10 mm width, 250 mm length) placed be-tween the cathode assemblies in the facility. In parallel  O.M. MOROZOV, V.G. KULISH, V.I. ZHURBA, ET AL. PROC. NAP 2, 04NEA04 (2013)   04NEA04-2 with the molybdenum foils there were arranged the copper plates (10 10 mm2) as standards for determin-ing the thickness of obtained samples by the gravimet-ric method and composite component concentrations – by the X -ray fluorescent method. Figure 2 represents the magnesium and titanium concentration in the Mg–Ti samples, measured by the method of X-ray fluorescence analysis, as a function of the distance between the magnesium and titanium cathodes.    Fig. 2 – Magnesium and titanium concentration in the Mg-Ti composite samples versus the distance between the magnesium and titanium cathodes  Deuterium introduction into the samples was per-formed by the ion implantation method. Deuterium desorption temperature ranges and deuterium storage levels were determined by the thermal desorption spec-troscopy. Deuterium introduction into the samples was performed by the ion implantation method. Deuterium desorption temperature ranges and deuterium storage levels were determined by the thermal desorption spec-troscopy.  In experiments a hydrogen isotope (deuterium) was used to decrease the influence of the background hydrogen contained in samples and target chambers. The samples were mounted on foils-heaters made of stainless steel Ch18Ni10Ti (5 45 0.3 mm3). The temperature was measured with a chromel-alumel thermocouple fastened to the heater.  3. RESULTS AND DISCUSSION  The most characteristic spectra of ion-implanted deuterium thermal desorption from the Mg-Ti composites are shown in Fig. 3. The figure demonstrates the thermal desorption spectrum (TDS) evolution from the composite composition and the implanted deuterium dose, as well as, the corresponding temperatures of maximum peaks in the deuterium TDS against the magnesium concentration in the samples under study. A low magnesium concentration and, consequently, a high titanium concentration in the composite are revealed in the deuterium TDS as a single peak with a maximum temperature at 800-950 K depending on the implanted deuterium dose and composite composition (Fig. 3 a, b). A single-peak character of the deuterium TDS, observed for magnesium concentration values ranging from 1 to 30 at. , evidences on the homogeneity of composite structural state in this range. As the magnesium concentration in the composites increases to the Mg30Ti70 composition, the maximum peak temperature in the deuterium TDS rises to the temperature of 950 K. So, the magnesium influence on the temperature range of deuterium trapping is increasing (see Fig. 3b).  The temperature range of deuterium desorption from the  magnesium- titanium  composites,  having   ahigh titanium content, on the temperature scale is within the region of the deuterium solid solution in α-titanium. Besides, for Mg30-хTi70+x  composites the peak maximum temperature displaces with implantation dose increasing in the deuterium TDS towards the temperature decrease that has been earlier observed for the titanium samples located at the substrate [19]. With a dose of 2 1018 D/cm2 there is in the deuterium TDS of Mg30-хTi70+x composites an additional low-intensity low-temperature slightly sloped peak with a centre of gravity at 300-400 К. This indicates on the fact that the process of deuterium solid-solution phase state formation in the composite has finished and the process of hydride formation has started. A step-like form of the maximum temperature curve obtained for the thermoactivated deuterium release from composites as a function of the magnesium concentration evidences on the existence of two different structural states of the system depending on the ratio of components. At the same time, in each of the states being observed a main role is performed by one of the components – magnesium or titanium. Analysis of the shapes of curves shown in Fig. 4, illustrating the change in the concentration of deuterium desorbed from  Mg30Ti70 (part I) and Mg83.5Ti16.5  (part II) composites, has shown an appreciable difference in the dependence on the ratio of composite components. In the concentration region where titanium (Mg30-хTi70+х composites) plays a prevailing role, one can see a linear growth of the amount of deuterium trapped due to the implantation dose increase. The foregoing permits to draw a conclusion about a high mobility of deuterium by diffusion in such composites and deuterium release from the implantation region and propagation throughout the sample volume.  A similar effect was observed for palladium at a temperature of deuterium implantation of 100 K [20]. In the case of Mg40+хTi60-х composites the amount of trapped deuterium is decreasing beginning from the dose of ~1 1018 D/cm2 with a tendency towards the attainment of saturation when the implantation dose exceeds 2 1018 D/cm2. It means that in this composite the implanted deuterium has the low diffusion mobility and its accumulation takes place mainly in the implantation volume.  The structure of deuterium TDS in the case of Mg40+хTiх composites strongly depends on the implanted deuterium dose. For the low implantation doses (3 1015 D/cm2) the spectrum has only one high-temperature peak with the centre of gravity at 850-900 K. The implanted deuterium dose increase is accompanied by the extension of the deuterium desorption temperature range towards the temperature decrease (Fig. 3d, curves 2 and 3). Beginning from the dose of 1 1017 D/cm2 there is observed a deuterium desorption region with a centre of gravity at 400 K.  The intensity of this peak continues to grow up to the dose of 9 1017 D/сm2. As the implanted deuterium dose  EFFECTS OF CONCENTRATION TITANIUM ON THRESHOLD … PROC. NAP 2, 04NEA04 (2013)   04NEA04-3 goes on, the amount of trapped deuterium decreases (see Fig. 4, curve 2) and an additional low-temperature region of deuterium desorption with a centre of gravity at 300-330 K appears (Fig. 3d, curve 7). The low-temperature intensity increases owing to the implanted deuterium and deuterium trapped before at a higher temperature. The changes observed in the deuterium TDS evidence on the structure transformation in the implantation layer.    Fig. 3 – Deuterium desorption temperature versus the Mg-Ti composition ( ) for a deuterium dose of 1 1018 D/cm2 (Tirr. 100 K) and thermal desorption spectra of deuterium released from composites: (a) Mg06Ti94; (b) Mg30Ti70; (c) Mg41Ti59; (d) Mg66.5Ti33.5     Fig. 4 – Amount of desorbed deuterium versus the implanted dose for the Mg30Ti70 (1- ) and Mg83.5Ti16.5 (2-  ) composites  An additional low-temperature peak in TDS, which becomes prevailing with the implanted deuterium dose increasing and reaches the maximum desorption temperature of the main low-temperature peak 300 K, arises due to the temperature decreasing during deuterium desorption from the Mg-Ti composites having the titanium concentration less than 60 at. .The deuterium temperature decrease can be caused by filamentary inclusions of insoluble component atoms (titanium in our case) formed, in the process of composite making and annealing, which provide the deuterium diffusion from the sample at a lower temperature (channels for deuterium diffusion through the surface barrier).  4. CONCLUSIONS  The present paper shows that by introducing titanium into magnesium the deuterium desorption temperature can be significantly decreased (to 400-450 K) compared to desorption from the magnesium samples ( 800 K). A step-like shape of the maximum temperature curve of thermoactivated deuterium desorption as a function of the component concentration change evidences on the presence of two different structure states of the Mg-Ti system depending on the ratio of components. The deuterium temperature decrease can be caused by filamentary inclusions of insoluble component atoms, formed in the process of making and annealing, which provide the deuterium diffusion from the sample at a lower temperature (channels for deuterium diffusion through the surface barrier). The deuterium desorption data obtained using Mg-Ti, Mg-V [15] and Mg-Zr [16] composites provide support for further research into the hydrogen storage materials containing low-soluble chemical elements in the alloy components.    O.M. MOROZOV, V.G. KULISH, V.I. ZHURBA, ET AL. PROC. NAP 2, 04NEA04 (2013)   04NEA04-4 ACKNOWLEDGEMENT  This study has been done with financial support to the program at the National Academy of Sciences of Ukraine “Hydrogen in the alternative energy and new technologies” (Project #27-13).  REFERENCES  1. J. Huot, D.B. Ravnsbæk, J. Zhang, F. Cuevas, M. Latroche, T.R. Jensen. Prog. Mater. Sci. 58, 30 (2013). 2. K. Asano, H. Enoki, E. Akiba, J. Alloys Compd. 480, 558 (2009). 3. H. Shao, G. Xin, J. Zheng, X. Li, E. Akiba, Nano Energy 1, 590 (2012). 4. M. Anik, F. Karanfil, N. Kucukdeveci, Int. J. Hydrogen Energy 37, 299 (2012). 5. O. Ershova, V. Dobrovolsky, Yu. Solonin, O. Khyzhun, A. Koval, J. Alloys Compd. 464, 212 (2008). 6. S.X. Tao, P.H.L. Notten, R.A. van Santen and A.P.J. Jansen, Phys. Rev. 83B, 195403 (2011). 7. C. Zlotea, F. Cuevasa, J. Andrieux, C. Ghimbeu, E. Leroy, E. Leonel, S. Sengmany, C. Vix-Guterl, R. Gadiou, T. Martens, M. Latroche. Nano Energy 2, 12 (2013). 8. S.D. Vincent, J. Lang, J. Huot. J. Alloys Compd. 512, 290 (2012). 9. M. Anik, F. Karanfil, N. Kucukdeveci. Int. J. Hydrogen Energy, 37, 299 (2012). 10. Y. He, Y. Liu and Y. Zhao, Nanotechnology 19, 465602 (2008). 11. P. Pei, X. Song, J. Liu, A. Song, P. Zhang, G. Chen, Int. J. Hydrogen Energy 37, 984 (2012). 12. M.S. Park, A. Janotti, and C.G. Van de Walle, Phys. Rev. 80B, 064102 (2009). 13. L. Pasquini, M. Brighi, A. Montone, M.V. Antisari, B. Dam, V. Palmisano and E. Bonetti, IOP Conf. Series: Mat. Sci. Eng., 38, 012001 (2012). 14. M.G. Shelyapina, D. Fruchart, S. Miraglia, and G. Girard, Phys. Solid State 53, 6 (2011). 15. I.M. Neklyudov, O.M. Morozov, V.G. Kulish, V.I. Zhurba, A.G. Galitskiy, N.S. Lomino, A.S. Kuprin, V.D. Ovcharenko, E.N. Reshetnyak, IOP Conf. Ser.: Mater. Sci. Eng. 38, 012028 (2012) 16. I.M. Neklyudov, O.M. Morozov, V.G. Kulish, V.I. Zhurba, N.S. Lomino, V.D. Оvcharenko and O.S. Кuprin, IOP Conf. Ser.: Mater. Sc.i Eng. 23 012028 (2011). 17. R. Varin, T. Czujko, Z. Wronski, Nanomaterials for Solid State Hydrogen Storage (Springer: 2009). 18. 1999 State diagrams of double metal systems vol 3-1 ed. N.P. Lyakishev (Moscow: Mashinostroyenie) [in Russian] 19. I.M. Neklyudov, O.M. Morozov and V.G. Kulish Materi-alovedenie 11, 45 (2000) [in Russian]. 20. V.F. Rybalko, A.N. Morozov, I.M. Neklyudov, V.G. Kulish, Phys. Lett. 287A, 175 (2001).   

https://essuir.sumdu.edu.ua/bitstream/123456789/35502/1/Morozov_Kulish_Zhurba.pdf

Effects of Concentration Titanium on Threshold Character of Deuterium Desorption Temperature Range from Mg-based Composites

Abstract

Similar works

Full text

Available Versions

SocioEconomic Challenges Journal (Sumy State University)

Electronic Sumy State University Institutional Repository