کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1619562 | 1005722 | 2011 | 4 صفحه PDF | دانلود رایگان |

The detailed kinetic analysis of formation and decomposition of powder magnesium hydride has shown that in contrast to conventional coarse-grained magnesium in which particles seem to react independently from each other, contacts between particles are important at hydriding of nanostructural magnesium because it facilitates the nucleation process hampered in nano-sized particles.The cooperative effects have been revealed also at decomposition of powder magnesium hydride. Being limited by recombination and desorption of hydrogen, the reaction of decomposition of magnesium hydride starts on the particles containing metal impurities or being in contact with the metal surface of container. The nuclei of metallic magnesium formed in these particles initiate the nucleation in the neighboring particles being in contact with them. Nucleation propagates like a chain process. Separation of particles by dilution of the sample by inert additive leads to considerable decrease of the reaction rate.
Research highlights▶ Cooperative effects have been revealed at decomposition of powder magnesium hydride. ▶ Magnesium nucleus formed in one particle initiates nucleation in neighbouring one. ▶ Material of the sample holder can affect the kinetics of dehydriding reaction. ▶ Cooperative effects do not appear at hydriding of coarse-grained magnesium. ▶ Contacts between particles facilitate nucleation at hydriding of nano-sized magnesium.
Journal: Journal of Alloys and Compounds - Volume 509, Supplement 2, September 2011, Pages S576–S579