TY - JOUR

T1 - Kinetics of hydrogen liberation from stoichiometric and nonstoichiometric magnesium hydride

AU - Evard, E. A.

AU - Gabis, I. E.

AU - Murzinova, M. A.

PY - 2007/9/1

Y1 - 2007/9/1

N2 - We have carried out a systematic study of the kinetics of decomposition of stoichiometric and nonstoichiometric magnesium hydride. Using the thermal-desorption methods in barometric modification and mathematical modeling, we have shown that hydrogen desorption from stoichiometric MgH2 proceeds in two stages: the formation of nuclei of the metal phase and hydrogen liberation through surface islands of the metal phase under the limiting influence of desorption rate. In the course of hydrogen liberation from partially hydrogenated magnesium, the first stage is usually absent. We have established that the influence of other reactions on the overall degasification rate is at least much smaller than the effect of desorption from the surface of α-Mg. We have obtained estimates of the parameters affecting the desorption kinetics. Finally, we have shown that, for analysis of the kinetics of hydrogen liberation from MgH2, the choice of physically substantiated models has serious advantages as compared with the Avrami-Erofeev approach.

AB - We have carried out a systematic study of the kinetics of decomposition of stoichiometric and nonstoichiometric magnesium hydride. Using the thermal-desorption methods in barometric modification and mathematical modeling, we have shown that hydrogen desorption from stoichiometric MgH2 proceeds in two stages: the formation of nuclei of the metal phase and hydrogen liberation through surface islands of the metal phase under the limiting influence of desorption rate. In the course of hydrogen liberation from partially hydrogenated magnesium, the first stage is usually absent. We have established that the influence of other reactions on the overall degasification rate is at least much smaller than the effect of desorption from the surface of α-Mg. We have obtained estimates of the parameters affecting the desorption kinetics. Finally, we have shown that, for analysis of the kinetics of hydrogen liberation from MgH2, the choice of physically substantiated models has serious advantages as compared with the Avrami-Erofeev approach.

UR - http://www.scopus.com/inward/record.url?scp=49349106942&partnerID=8YFLogxK

U2 - 10.1007/s11003-008-9002-5

DO - 10.1007/s11003-008-9002-5

M3 - Article

AN - SCOPUS:49349106942

VL - 43

SP - 620

EP - 633

JO - Materials Science

JF - Materials Science

SN - 1068-820X

IS - 5

ER -