Electronic structure of Sr2−La FeMoO6

Saitoh, T.; Nakatake, M.; Nakajima, Hideki; Morimoto, Osamu; Kakizaki, Akito; Xu, Shi; Moritomo, Yutaka; Hamada, Nobuyuki; Aiura, Y.

doi:10.1016/j.elspec.2005.01.216

Cited by 10 publications

(9 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The previous studies of Fe-Mo DP using the photoemission spectroscopy (PES) show that the distance between occupied Fe 3d e g and t 2g spin up states is about 2 eV and the distance between Fe 3d states and O 2p states is about 5 eV [26,59,62,32,34]. Thus, the pre-peak A in the Fe XANES spectra can be attributed to the 4p states hybridised with oxygen 2p states and iron t 2g spin up states, whereas the pre-peak A can be assigned to the 4p states hybridised with iron e g spin up and t 2g spin down states.…”

Section: Xanes Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Local Magnetic and Electronic Properties of the A2FeM'O6 (A = Ba, Sr, Ca, M' = Mo, Re) Double Perovskites

et al. 2007

View full text Add to dashboard Cite

The results of a combined NMR, X-ray absorption spectroscopy and X-ray magnetic circular dichroism study of the AA FeMoO6 and AA FeReO6 double perovskites are presented. They revealed a dependence of electronic and magnetic properties, including a d-electron transfer between Fe and Mo sites, on the structural tolerance factor. The maximum value of the 4d Mo electron occupation and the corresponding Mo moment is obtained for the tolerance factor of unity. This corresponds to the maximum strength of the magnetic interaction and, respectively, to the Curie temperature. The dominant T 5/2 type temperature dependence of the Mo hyperfine field reveals the half-metallicity of the AA FeMoO 6 compounds. Antisite defects and antiphase boundaries have been identified in NMR measurements and the strength of their magnetic coupling have been determined. A considerable orbital contribution to the Re and Fe magnetic moments were found in the NMR and X-ray magnetic circular dichroism measurements on the AA FeReO6 compounds. Its magnitude decreases with increasing structural tolerance factor and is correlated with their magnetic anisotropy. IntroductionDouble perovskites (DP) of a general formula A 2 MM O 6 , where A is an alkaline earth, and M and M are 3d, 4d, and/or 5d transition metals belong to a very broad family of oxide compounds crystallising in the perovskite structure. They exhibit intriguing magnetic and electronic properties including half metallicity, a considerable low field magnetoresistance (LFMR) and a variety of magnetic structures, see review paper [1]. Magnetic and electronic properties are closely interrelated, due to the same (d) character of the "magnetic" and "conduction" electrons. Exchange interactions can occur between ions of the same element, as e.g. in manganese perovskites, as well as between ions of different elements, as e.g. in double perovskites. The interplay of lattice, charge, and spin degrees of freedom causes a variety of electronic and magnetic properties ranging from a metallic ferro-or ferrimagnetism to antiferromagnetic or paramagnetic insulating behaviour. This also brings about the magnetoresistive properties of the compounds.The interplay between magnetic and electronic transport properties in these systems can be controlled by substitution of alkaline earths (e.g. Ba, Sr, Ca) or lanthanides (e.g. La, Pr, Nd) in the A-site, as well as by the substitution of transition metals (e.g. Fe, Cr, Mn, Mo, Rh, Ru, W, Re). Among the double perovskites, the Fe-Mo and Fe-Re compounds, which are the subject of the study presented in this paper, have recently attracted a great deal of interest among the researchers. Their relatively high magnetic ordering temperature (in most cases higher than the room temperature) compared to that of manganese perovskites, and a significant LFMR make them especially interesting for applications, e.g. in magnetoelectronics or spintronics. The LFMR is explained in terms of intergranular tunneling MR (ITMR), and is related to the half-metallic nature of the ground...

show abstract

Section: Xanes Results and Discussionmentioning

confidence: 99%

“…The electronic properties of the Fe-Mo and Fe-Re double perovskites have been studied theoretically and experimentally by several authors [25][26][27][28][29][30][31][32][33][34]. The calculations of the density of states (DOS) reveal a gap in the majority spin band at the Fermi level.…”

mentioning

confidence: 99%

Local Magnetic and Electronic Properties of the A2FeM'O6 (A = Ba, Sr, Ca, M' = Mo, Re) Double Perovskites

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Attempts have been made to electron dope this compound (SFMO) hoping to enhance the T c and hence the polarization at room temperature and thereby improve the magnetoresistance. [8][9][10][11] . While a slight increase in T c is indeed observed for low dopings 10,12 , but for overdoping (x > 1), the T c is found to decrease,as shown in 13,14 , and the ferromagnetism gets replaced by antiferromagnetic phases.…”

Section: Introductionmentioning

confidence: 99%

Antiferromagnetic metal phases in double perovskites having microscopic phase segregation due to strong antisite defect concentration

Sanyal

2015

Eur. Phys. J. B

View full text Add to dashboard Cite

Recently an antiferromagnetic metal phase has been proposed in double perovskites materials like Sr2FeMoO6 (SFMO), when electron doped. This material has been found to change from half-metallic ferromagnet to antiferromagnetic metal (AFM) upon La-overdoping. The original proposition of such an AFM phase was made for clean samples, but the experimental realization of La-overdoped SFMO has been found to contain a substantial fraction of antisite defects. A phase segregation into alternate Fe and Mo rich regions was observed. In this paper we propose a possible scenario in which this type of strong antisite concentration can still result in an antiferromagnetic metal phase, by a novel hopping driven mechanism. Using variational calculations, we find that proliferation of such phase segregated domain regions can also result in the stabilization of an A-type AFM over the G-type AFM based on kinetic energy considerations.PACS numbers:

show abstract

“…The high T c implies a strong polarization even at room temperatures, enhancing its industrial importance. In an effort to boost the T c even further, researchers have electron doped this compound [8][9][10]12 . Although the T c does increase in this process upto some point 10,11 , but it has been shown in a recent work that upon overdoping, the T c actually decreases, and the ferromagnetism becomes unstable 13,14 !…”

Section: Introductionmentioning

confidence: 99%

Understanding ferromagnetism in Cr-based 3d-5d double perovskites

Sanyal

2012

Preprint

View full text Add to dashboard Cite

Ferromagnetism in Cr-based double perovskites is analyzed using effective model as well as simulation approach. Starting from a microscopic model proposed recently for this class of double perovskites, an effective spin-only model is derived in the limit of large exchange coupling at the B-site. Analytic expressions for the resultant exchange coupling is derived in certain limiting cases. The behaviour of this exchange is used to provide a plausible explanation for the enhanced ferromagnetic tendency as also the enigmatic increase in Curie temperature observed in Cr-based DP-s, in the series Sr2CrWO6,Sr2CrReO6 to Sr2CrOsO6. The superexchange between neighbouring B and B' sites is found to play a crucial role both in stabilizing ferromagnetism, especially in the latter two compounds, as well as increasing the Tc.

show abstract

Electronic structure of Sr2−La FeMoO6

Cited by 10 publications

References 14 publications

Local Magnetic and Electronic Properties of the A2FeM'O6 (A = Ba, Sr, Ca, M' = Mo, Re) Double Perovskites

Local Magnetic and Electronic Properties of the A2FeM'O6 (A = Ba, Sr, Ca, M' = Mo, Re) Double Perovskites

Antiferromagnetic metal phases in double perovskites having microscopic phase segregation due to strong antisite defect concentration

Understanding ferromagnetism in Cr-based 3d-5d double perovskites

Contact Info

Product

Resources

About