2012
Carvajal, E.; Oviedo-Roa, R.; Cruz-Irisson, M.; Navarro, O.
FeMo double perovskite: From small clusters to bulk material Artículo de revista
En: Materials Science and Engineering: B, vol. 177, no 16, pp. 1514-1517, 2012, ISSN: 0921-5107, (Advances in Semiconducting Materials).
Resumen | Enlaces | BibTeX | Etiquetas: Bulk material, Density Functional Theory, Double perovskites, Half-metallic ferromagnetism, Small clusters
@article{CARVAJAL20121514,
title = {FeMo double perovskite: From small clusters to bulk material},
author = {E. Carvajal and R. Oviedo-Roa and M. Cruz-Irisson and O. Navarro},
url = {https://www.sciencedirect.com/science/article/pii/S0921510712002048},
doi = {https://doi.org/10.1016/j.mseb.2012.03.041},
issn = {0921-5107},
year = {2012},
date = {2012-01-01},
urldate = {2012-01-01},
journal = {Materials Science and Engineering: B},
volume = {177},
number = {16},
pages = {1514-1517},
abstract = {To understand the differences in behaviour between up- and down-spin electrons observed in the half-metallic Sr2FeMoO6 double perovskite, the density of states (DOS) was studied for the (FeO6)−4 and (MoO6)−6 octahedral clusters using first-principles density functional theory within the generalised gradient approximation (GGA) scheme and the Perdew\textendashBurke\textendashErnzerhof (PBE) functional. Our results reveal that half-metallic character is present, even starting from an isolated (FeO6)−4 cluster, and is a consequence of spin decoupling of antibonding hybridisations between iron t2g states and oxygen p states (t2ga states), i.e., t2ga states lie below the Highest Occupied Molecular Orbital (HOMO) in the up-spin channel, whereas they lie above the HOMO level in the down-spin channel. The spin-induced shifting between up-spin and down-spin DOS situates the HOMO in such a way that the molecular orbitals oxygen p states (p bands) are fully spin-paired by octet electrons. Thus, the down-spin channel has metallic character because the HOMO lies just at the p bands, and the up-spin channel is semiconducting because the HOMO falls within the energy gap between the t2ga and ega bands. Finally, the (MoO6)−6 octahedron does not inhibit the perovskite half-metallic character since this cluster has a zero total spin.},
note = {Advances in Semiconducting Materials},
keywords = {Bulk material, Density Functional Theory, Double perovskites, Half-metallic ferromagnetism, Small clusters},
pubstate = {published},
tppubtype = {article}
}
To understand the differences in behaviour between up- and down-spin electrons observed in the half-metallic Sr2FeMoO6 double perovskite, the density of states (DOS) was studied for the (FeO6)−4 and (MoO6)−6 octahedral clusters using first-principles density functional theory within the generalised gradient approximation (GGA) scheme and the Perdew–Burke–Ernzerhof (PBE) functional. Our results reveal that half-metallic character is present, even starting from an isolated (FeO6)−4 cluster, and is a consequence of spin decoupling of antibonding hybridisations between iron t2g states and oxygen p states (t2ga states), i.e., t2ga states lie below the Highest Occupied Molecular Orbital (HOMO) in the up-spin channel, whereas they lie above the HOMO level in the down-spin channel. The spin-induced shifting between up-spin and down-spin DOS situates the HOMO in such a way that the molecular orbitals oxygen p states (p bands) are fully spin-paired by octet electrons. Thus, the down-spin channel has metallic character because the HOMO lies just at the p bands, and the up-spin channel is semiconducting because the HOMO falls within the energy gap between the t2ga and ega bands. Finally, the (MoO6)−6 octahedron does not inhibit the perovskite half-metallic character since this cluster has a zero total spin.
