INVESTIGADORES
LANERI Karina Fabiana
artículos
Título:
Distribution of interstitial atoms in FCC FeN alloys: A Mossbauer, thermodynamic and Monte Carlo approach
Autor/es:
L. VERGARA ; J. DESIMONI ; K. LANERI ; A. FERNANDEZ GUILLERMET ; G.J. ZARRAGOICOECHEA
Revista:
PHYSICA B - CONDENSED MATTER
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2005 vol. 363 p. 178 - 189
ISSN:
0921-4526
Resumen:
A study is presented of the distribution of interstitial atoms in the octahedral sites of the face-centered-cubic (FCC) austenite phase in FeN system. The approach is based on the interplay between an analysis of Mossbauer data, Monte Carlo (MC) simulations, analytical calculations based on the quasichemical approximation (QCA) to the statistical
mechanics of interstitial solutions, and thermodynamic activity data. A database is developed, with analyses of Mossbauer spectra using models assuming either ordered or random distributions of the N atoms in the interstices around an Fe atom. The experimental trends are confronted with predictions of a combined theoretical approach.
Thermodynamic activity data are analyzed, and the energies of the NN pairs thus obtained are used in both MC simulations and QCA calculations, which are adopted as a suitable frame of reference for the critical comparison between the FeN and FeC systems. Monte Carlo predictions of the relative fractions of the FeN environment reveal that the consideration of only NN interactions, as in the case of the FeC system, is not enough to describe the FeN austenite. Various implications of the present results are discussed.