IFLYSIB   05383
INSTITUTO DE FISICA DE LIQUIDOS Y SISTEMAS BIOLOGICOS
Unidad Ejecutora - UE
artículos
Título:
The magnetization of g'-Fe4N: theory vs. experiment
Autor/es:
E. L. PELTZER Y BLANCÁ; J. DESIMONI; N.E.CHRISTENSEN; H.EMMERICH; S.COTTENIER
Revista:
PHYSICA STATUS SOLIDI B-BASIC RESEARCH
Editorial:
WILEY-V C H VERLAG GMBH
Referencias:
Lugar: Londres; Año: 2009 vol. 246 p. 906 - 928
ISSN:
0370-1972
Resumen:
By reviewing the experimental and theoretical literature on
Á-Fe4N, and by a systematic survey of predictions by the
LDA, PBE, WC, LDA + U (2~), PBE + U (2~) and B3PW91
exchange-correlation functionals, the structural, magnetic and
hyperfine properties of this material as well as their pressure
dependencies are interpreted. The hypothesis is put forward
that Á -Fe4N as found in Nature is exactly at a steep transition
between low-spin and high-spin behaviour. PBE + U
(U = 0.4 eV) is identified as the most accurate exchangecorrelation
functional for this material, although it is needed
to fix the magnetization at the experimental value to obtain a
satisfying description. Remaining disagreement between theory
and experiment is pointed out. A recent experimental
claim for a giant magnetic moment in Á -Fe4N is discussed,
and is not reproduced by our calculations. We expect that the
new insight obtained in the present work can lead to a consistent
ab initio modeling of other materials in the iron-nitrogen
binary system. In an accompanying didactic section, the physics
behind some common exchange-correlation functionals is
outlined.