Abstract
The interrelationship between coherency and solute segregation at metal/metal-nitride heterophase interfaces is studied on a subnanometer scale by both atom-probe field-ion and electron microscopies for molybdenum nitride precipitates in Fe-2at% Mo-X, where X=0.4at% Sb or 0.5at% Sn. Internal nitridation at 550°C generates thin platelet-shaped molybdenum nitride precipitates, while nitridation at 600°C produces, in addition to the small-scale structure with precipitates of the thin-platelet type, a much coarser structure of thick plates and spheroidal precipitates. The solute species Sn and Sb segregate at the heterophase interfaces of the coarse precipitates and Gibbsian interfacial excesses of up to 7×1018m-2 are measured. The segregation is related to the presence of misfit dislocations at the interfaces of the coarse preciptitates, while the thin plates remain coherent with no detectable segregation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 195-202 |
| Number of pages | 8 |
| Journal | Ultramicroscopy |
| Volume | 89 |
| Issue number | 1-3 |
| DOIs | |
| State | Published - 2001 |
Funding
This research was supported by the National Science Foundation (Bruce A. MacDonald, grant officer). E.J.S. was supported by an NSF REU grant. D.I. received partial support through the Max Planck Research Prize of D.N.S. and from the Deutsche Forschungsgemeinschaft. The authors wish to thank Ms. P. Epps, Mr. M. Potter, Mr. A. Pyzyna, Mr. E. Spoerke and Ms. I. Uttayarat for their contributions to this research as a result of a series of undergraduate research projects, which were partially supported by the REU program of the National Science Foundation.
Keywords
- Atom-probe field-ion microscopy
- Internal interfaces
- Internal nitridation
- Solute segregation
- Transmission electron microscopy
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Instrumentation
- Atomic and Molecular Physics, and Optics