Martensitic Phase Transitions in Nanocrystalline Materials
Abstract
As indicated in our third interim report, we have carried out Mossbauer spectroscopy on isolated nanometer-sized crystals cooled to 4.2 K under ultra-high vacuum conditions in order to decide whether or not nucleation of martensite is possible in nanometer-sized, unconstrained crystals. The spectrometer necessary to carry out those experiments was developed in January 1988. It consists of a quartz tube which has locally a section of two thin walls which are transparent to the Mossbauer gamma-rays. The loose powder of isolated small crystals is filled under UHV conditions into the tube and is subsequently cooled to 4.2 K. However, when we recorded the Mossbauer spectra, they turned out not to be conclusive for two reasons. (1) The isolated 5 nm Fe-Ni crystals are superparamagnetic at 4.2 k. (2) The resolution of the spectra is not as high as required to distinguish between bcc and fcc FeNI due to the small amount of material in the tube. Iron, Nickel.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 02, 1988
- Accession Number
- ADA203636
Entities
People
- H. Gleiter