CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

A generic statistical model of hydride formation in a random alloy

Vladimir P. Zhdanov (Institutionen för fysik, Kemisk fysik (Chalmers))
Modern Physics Letters B (0217-9849). Vol. 30 (2016), 26,
[Artikel, refereegranskad vetenskaplig]

Hydride formation in metals (e.g. in Pd), accompanied by a hysteresis loop in the absorption isotherms, is one of the generic examples of first-order phase transitions (FOPTs). During the last decade, the corresponding experimental studies, driven by applications related to hydrogen storage, have shifted towards metal particles sized from a few nanometers to micrometers in general and to alloyed particles of these sizes in particular. The understanding of hydride formation in alloys is, however, still far from complete. Herein, a statistical model of hydride formation in a random alloy is presented. The model is focused on the situation when this process is favorable in metal 1 (e.g. Pd) and shows what may happen when atoms of metal 2 make it less favorable due to decrease of the hydrogen binding energy and/or attractive hydrogen hydrogen (H-H) interaction. Random distribution of metal atoms is taken explicitly into account. The attractive H-H interaction, including its dependence on fraction of metal 2 in the alloy, is described at the mean-field level. With increasing fraction of the latter metal, the critical temperature is found to decrease linearly or nonlinearly depending on the values of the model parameters. If the decrease of the hydrogen binding energy with increasing number of nearest-neighbor (nn) atoms of metal 2 is appreciable, the model predicts up to three hysteresis loops.

Nyckelord: First-order phase transitions, alloys, hydride formation, absorption isotherms, hydrogen absorption, phase-equilibria, systems, nanoparticles, metal, thermodynamics, hysteresis



Denna post skapades 2016-11-16.
CPL Pubid: 245266

 

Läs direkt!


Länk till annan sajt (kan kräva inloggning)


Institutioner (Chalmers)

Institutionen för fysik, Kemisk fysik (Chalmers)

Ämnesområden

Atom- och molekylfysik och optik

Chalmers infrastruktur