Author: abracadabra
Last saved by: 1
Company: Hewlett-Packard

Specialization: 010700/03 Physics of condensed matter
Program: 27 Magnetic resonance. Physical aspects and applications
Program Manager: Prof., Dr. V. I. Chizhik
Department of Quantum Magnetic Phenomena
Supervisor: Dr. M.G. Shelyapina
Referee:  S.A. Lavrov

Proton nuclear magnetic resonance studies of hydrogen site occupancies and
 mobility in binary disordered titanium-vanadium hydrides 
Elena Kurenkova 
           
We report on the results of our recent cw  and  pulse  ^1H NMR studies of hydrides of binary Ti-V alloys of interest for reversible hydrogen storage applications. All studied samples were synthetized using the method of Self-propagating High-temperature Synthesis [3]. According to the X-ray diffraction analysis Ti_1-xV_x alloys (with x = 0.4, 05, 0.6, 0.8, 0.9) have bcc structure, whereas their hydrides Ti_1-xV_xH_y (with y close to 2) have fcc structure. Analysis of the second moment of the ^1H NMR adsorption line has proved that bonded hydrogen atoms are located on two types of positions - octahedral and tetrahedral. At low concentrations of vanadium is almost all hydrogen (90%) occupies the tetrahedral positions, but with increasing concentration of vanadium, the share of employment octahedral positions increases (up to 20%). 
Temperature dependences of proton spin-laticce relaxation times T_1 were measured over temperature range 190- 380 K  at frequency 20 MHz. Determination of the spin-lattice time  in the whole temperature range for all objects of the study showed that there are two components of the T_1, which differ by an order. Analysis of the intensities of the components of the relaxation times was suggested that in the exchange model, these contributions can be correlated with the signals from the nuclei 1H, participating in an exchange with the nuclei localized in either the octahedral or tetrahedral position and in the investigated temperature range hydrides have several structural phase transitions.

The list of the publications
1.	Kurenkova Е.V., Shelyapina M.G. “ Crystal structure and mobility of hydrogen in Zr_7Ni_10 and Hf_7Ni_10” (in Russian).  6^th student school-conference “Magnetic resonance and its applications”, St.Peterburg, Book of Abstracts, p.185-187 (2009). 
2.	Kurenkova Е.V., Shelyapina M.G., Kasperovich V.S. “1H NMR line shape in a saturated hydrides  of disordered binary alloys Ti_1-xV_x” (in Russian). 7^th student school-conference “Magnetic resonance and its applications”, St.Peterburg, Book of Abstracts, p.171-173 (2010).
3.	A. Danilova, E. Kurenkova, A. Vyvodceva, V.S. Kasperovich, M.G. Shelyapina, A.V. Ievlev,  A. G. Aleksanyan, S. K. Dolukhanyan, N.E. Skryabina “ ^1H NMR study of hydrides of binary Ti-V  disordered alloys  synthesized by the SHS method ”.  International Symposium Nuclear Magnetic Resonance in Condensed Matter, NMRCM-2011, 27 June – 1 July, 2011, St-Petersburg, Russia, Book of abstracts, p. 55, (2011).
4.	E. Kurenkova, V.S. Kasperovich , M.G. Shelyapina , S. A. Lavrov,  A. G. Aleksanyan, S. K. Dolukhanyan, N.E. Skryabina , D. Fruchart  “A  CW  ^1H NMR study of hydrides of binary Ti-V alloys” International conference “Resonance in condensed matter” June 21-25, 2011, Russia, Kazan. Book of abstracts p. 103.
5.	Vyvodceva А. V., Kurenkova Е.V., Danilova А.V., Shelyapina M.G.  “Spin-lattice relaxation ^1H in hydrides of binary alloys Ti_1-xV_x ” (in Russian). 8^th student school-conference “Magnetic resonance and its applications”, St.Peterburg, Book of Abstracts, p.135-137 (2011).
6.	V.S. Kasperovich, M.G. Shelyapina, B. Khar’kov, I.A. Rykov, V. Osipov, E. Kurenkova, A.V. Ievlev, N.E. Skryabina, D. Fruchart, S. Miraglia, P. de Rango, “NMR study of metal-hydrogen systems for hydrogen storage”, Journal of Alloys and Compounds 509S (2011) S804–S808  doi:10.1016/j.jallcom.2010.10.195
7.	E. Kurenkova, A. Vyvodtseva, M.G. Shelyapina, V.I. Chizhik,A.V. Ievlev, N.E.  Skryabina, A.G. Aleksanyan, D. Fruchart  ” ^1H NMR study of hydrogen site occupancy in hydrides of disordered  Ti-V and Ti-V-Cr alloys”. Solid State Phenomena, 2012. (accepted)
8.	Kurenkova Е.V., Shelyapina M.G., Vyvodceva А. V., Ievlev A.V., “Spin-lattice relaxation ^1H in hydrides of binary alloys Ti_1-xV_x ” (in Russian). Russian scientific conference of physics students-18, Krasnoyarsk, Book of Abstracts, p.141 (2012). 
9.	A.V. Vyvodtceva, E.V. Kurenkova, M.G. Shelyapina, NMRCM-2012, 09  – 13 July.Book of Abstracts  (2012). (accepted)
10.	E.V. Kurenkova, A.V. Vyvodceva, M.G. Shelyapina, S.A. Lavrov, A.V. Ievlev,     V.I.Chizhik, A.G. Aleksanyan^1, S.K. Dolukhanyan^1, N.E. Skryabina^2. “Proton NMR study of Ti_1-xV_xH_y hydrides: hydrogen site occupancy and mobility ”. NMRCM-2012, 09  – 13 July.Book of Abstracts  (2012). (accepted)