Thermal vacancy formation and D03 ordering in nanocrystalline intermetallic (Fe3Si)95Nb5
Abstract
The correlation between thermal vacancy characteristics and D0(3) ordering in ball-milled nanocrystalline (Fe3Si)(95)Nb-5 was studied by combined measurements of x-ray diffraction and positron annihilation. Structural stabilization due to grain boundary segregation of Nb enables high-temperature positron lifetime measurements up to 1023 K from which vacancy formation parameters identical to those in single-crystalline D0(3) Fe3Si are deduced. Measurements of coincidence Doppler broadening show that prior to the onset of thermal defect formation in the nanocrystallites, positrons are annihilated in Nb-enriched grain boundaries. The D0(3) ordering of the initially disordered Fe3Si nanocrystallites is discussed on the basis of the thermal vacancy characteristics and self-diffusion behavior.
Additional Information
© 2001 The American Physical Society. Received 22 September 2000; revised 15 December 2000; published 15 March 2001. We thank W. Sprengel and M. Eggersmann for helpful discussion and N. Karl for providing the opportunity to perform the x-ray measurements. This work was financially supported by the University of Bologna (L.P.), Max-Planck-Gesellschaft and RFBR Grant No. 99-03-32208a (A.A.R.), Deutsche Forschungsgemeinschaft (Grants Scha428/8-2, 25-1), and European Union (Grant INTAS99-1216).Attached Files
Published - PASprb01.pdf
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Additional details
- Eprint ID
- 3688
- Resolver ID
- CaltechAUTHORS:PASprb01
- University of Bologna
- Max-Planck-Gesellschaft
- 99-03-32208a
- Russian Foundation for Basic Research
- Deutsche Forschungsgemeinschaft (DFG)
- INTAS99-1216
- European Union
- Created
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2006-06-29Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field