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 ƒÁŒ-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 ƒÁ Œ-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 ƒÁ Œ-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.