TY - JOUR

T1 - Proton NMR study of hydrogen mobility in (TiCr1.8)1-xVx hydrides

AU - Shelyapina, M. G.

AU - Skryabina, N. E.

AU - Surova, L. S.

AU - Dost, A.

AU - Ievlev, A. V.

AU - Privalov, A. F.

AU - Fruchart, D.

PY - 2019/3/25

Y1 - 2019/3/25

N2 - A series of (TiCr1.8)1-xVx alloys with x = 0.2, 0.4, 0.6 and 0.8 was synthetized by induction melting of a mixture of TiCr1.8 alloy and pure V. It has been found that after hydrogenation all the compounds turn into bct structure. The present bct metal hydrides could be considered forming a pre-martensite state during the transformation (Ti-V-Cr)Hxmin (bcc) ↔ (Ti-V-Cr)Hxmax (fcc). Proton NMR studies reveal that distribution of hydrogen over all samples is not homogeneous. The modified Bloembergen-Purcell-Pound model, which supposes existence of two hydrogen fractions in different metal environment, provides the lowest averaged activation energy of hydrogen motion corresponding to (TiCr1.8)0.6V0.4, the composition that exhibits the highest reversible hydrogen capacity. Following a regularity in changes of both structural parameters of the studied compounds before and after hydrogenation and those parameters that answer for hydrogen mobility we anticipate the existence of a percolation threshold in properties of the alloys (close to the compositions x = 0.4÷0.5).

AB - A series of (TiCr1.8)1-xVx alloys with x = 0.2, 0.4, 0.6 and 0.8 was synthetized by induction melting of a mixture of TiCr1.8 alloy and pure V. It has been found that after hydrogenation all the compounds turn into bct structure. The present bct metal hydrides could be considered forming a pre-martensite state during the transformation (Ti-V-Cr)Hxmin (bcc) ↔ (Ti-V-Cr)Hxmax (fcc). Proton NMR studies reveal that distribution of hydrogen over all samples is not homogeneous. The modified Bloembergen-Purcell-Pound model, which supposes existence of two hydrogen fractions in different metal environment, provides the lowest averaged activation energy of hydrogen motion corresponding to (TiCr1.8)0.6V0.4, the composition that exhibits the highest reversible hydrogen capacity. Following a regularity in changes of both structural parameters of the studied compounds before and after hydrogenation and those parameters that answer for hydrogen mobility we anticipate the existence of a percolation threshold in properties of the alloys (close to the compositions x = 0.4÷0.5).

KW - bct metal hydrides

KW - Hydrogen mobility

KW - Percolation threshold

KW - Ti-V-Cr alloys

KW - percolation threshold

KW - phd

KW - dr

KW - s institution

KW - saint-petersburg state university

KW - ti-v-cr alloys

KW - hydrogen mobility

KW - corresponding author

KW - marina g shelyapina

KW - V-H SYSTEM

KW - KNIGHT-SHIFT

KW - CRYSTAL-STRUCTURE

KW - NUCLEAR-MAGNETIC-RESONANCE

KW - BCT MONOHYDRIDE PHASE

KW - BAND-STRUCTURE

KW - LOCAL-STRUCTURE

KW - SPIN-LATTICE-RELAXATION

KW - STORAGE PROPERTIES

KW - CR ALLOYS

UR - http://www.scopus.com/inward/record.url?scp=85057102757&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/proton-nmr-study-hydrogen-mobility-ticrsub18subsub1xsubvsubxsub-hydrides

U2 - 10.1016/j.jallcom.2018.10.382

DO - 10.1016/j.jallcom.2018.10.382

M3 - Article

AN - SCOPUS:85057102757

VL - 778

SP - 962

EP - 971

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

SN - 0925-8388

ER -