Artículos de revistas
Particle Size Dependence Of The Pr2fe17 Nitrogenation Process
Registro en:
Hyperfine Interactions. Baltzer Science Publishers, Baarn/kluwer Academic Publishers, v. 83, n. 1, p. 209 - 215, 1994.
3043843
10.1007/BF02074274
2-s2.0-4243084913
Autor
Persiano A.I.C.
Ardisson J.D.
Mansur R.A.
Colucci C.C.
Gama S.
Institución
Resumen
The particle size dependence of the Pr2Fe17 nitrogenation process at 400°C is determined by the Mössbauer method. The experimental data are described in terms of a particle model consisting of spherical concentrical shells containing: (i) an expanded central core saturated with 2+e{open} atoms N per formula unit; (ii) an intermediate unnitrided shell with a volume larger than the core by a factor of about 2.4 and accommodating a stress/strain field produced by the expanded core, and (iii) an unnitrogenated undeformed external shell. We observed that small particles (d ≤ 10 ώm and most probably lower) tend to absorb higher nitrogen contents than the large ones. Our results also indicate that some small particles, most probably single crystals, do not nitrogenate. © 1994 J.C. Baltzer AG, Science Publishers. 83 1 209 215