Interface pinning causes the hysteresis of the hydride transformation in binary metal hydrides
Journal Article
·
· Physical Review Materials
- California Institute of Technology (CalTech), Pasadena, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL)
- Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Northwestern Univ., Evanston, IL (United States). Engineering Sciences and Applied Mathematics
- California Institute of Technology (CalTech), Pasadena, CA (United States)
Hydriding and dehydriding transitions in bulk and nanocrystalline binary metal hydrides were studied using the Pd-H model system by measuring pressure-composition isotherms with in situ x-ray diffractometry. Nanocrystalline Pd showed a smaller pressure hysteresis, solvus hysteresis, and hysteresis in lattice parameter, compared to bulk Pd. The time-dependence of pressure equilibration was measured after dosing with aliquots of hydrogen, giving equilibration times that were much faster in the single-phase regions than in the two-phase plateaus. In the broad two-phase plateaus, the pressure relaxations were exponential functions of time. An explanation of hysteresis is developed that is based on a dissipative potential barrier that impedes the motion of the interface due to interactions between lattice defects and the two-phase interface. The exponential pressure relaxations and hysteresis are consistent for this mechanism. For a simple model of the pinning potential, the potential barrier maximum is an order of magnitude less than typical grain boundary energies. These pinning effects are substantially different in the nanocrystalline Pd, suggesting differences in the hydriding mechanism.
- Research Organization:
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-76SF00515
- OSTI ID:
- 1778217
- Journal Information:
- Physical Review Materials, Journal Name: Physical Review Materials Journal Issue: 1 Vol. 5; ISSN 2475-9953
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
The disappearance of hysteresis for the hydride phase transition in palladium-nickel alloys
Thermodynamics of coherent open systems with applications to hydrides: The physical origin of hysteresis in absorption-desorption isotherms. [Final report]
Mechanical properties of palladium and palladium hydride
Journal Article
·
Sun Sep 01 00:00:00 EDT 1991
· Scripta Metallurgica; (United States)
·
OSTI ID:5502561
Thermodynamics of coherent open systems with applications to hydrides: The physical origin of hysteresis in absorption-desorption isotherms. [Final report]
Technical Report
·
Fri Dec 30 23:00:00 EST 1994
·
OSTI ID:435230
Mechanical properties of palladium and palladium hydride
Journal Article
·
Fri Feb 14 23:00:00 EST 1992
· Scripta Metallurgica; (United States)
·
OSTI ID:5574329