Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1499587 | Scripta Materialia | 2011 | 4 Pages |
The thermodynamics of structural phase transformations in thin films depends on the mechanical stress that can be released by plastic deformation. For thin films below a critical film thickness, plastic deformation is energetically unfavourable: thus, the system stays coherent and stress remains. For PdHc films less than 22 nm thick, a new situation emerges: while the interfaces between matrix and hydride precipitates remain coherent throughout the complete phase transition, misfit dislocations form between the hydride phase and the substrate.
► Stress evolving during phase transformation changes thermodynamic properties of thin films. ► We investigate stress relaxation mechanisms inPdHc thin films during hydrogen loading. ► Below 22 nm film thickness misfit dislocations emerge between hydride phase and substrate. ► Below 22 nm film thickness misfit dislocation loop formation around precipitates is not possible. ► This yields a new state of partial coherency in thin films.