Possible percolation and magnetoresistance in ordered double perovskite alloys Sr2Fe(W1−xMox)O6

Kobayashi, Kojiro; Okuda, Takashi; Tomioka, Y.; Kimura, Takeshi; Tokura, Y.

doi:10.1016/s0304-8853(00)00397-8

Cited by 109 publications

(103 citation statements)

References 19 publications

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“…It also implies that the 100% ordered double perovskites cannot be ferromagnetic. The latter observation is qualitatively consistent with the behavior of Sr 2 FeWO 6 , where almost perfect ordering of Fe and W coexists with an AFM ground state [64].…”

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confidence: 85%

Magnetic Interactions in Transition‐Metal Oxides

Solovyev

2003

ChemInform

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The correct understanding of the nature and dynamics of interatomic magnetic interactions in solids is fundamentally important. In addition to that it allows to address and solve many practical questions such as stability of equilibrium magnetic structures, designing of magnetic phase diagrams, the low-temperature spin dynamics, etc. The magnetic transition temperature is also related with the behavior of interatomic magnetic interactions. One of the most interesting classes of magnetic compounds, which exhibits the rich variety of the above-mentioned properties in the transition-metal oxides. There is no doubts that all these properties are related with details of the electronic structure. In the spin-density-functional theory (SDFT), underlying many modern first-principles electronic structure methods, there is a certain number of fundamental theorems, which in principles provides a solid theoretical basis for the analysis of the interatomic magnetic interactions. One of them is the magnetic force theorem, which connects the total energy change with the change of single-particle energies obtained from solution of the KohnSham equations for the ground state. The basic problem is that in practical implementations SDFT is always supplemented with additional approximations, such as local-spin-density approximation (LSDA), LSDA + Hubbard U , etc., which are not always adequate for the transition-metal oxides. Therefore, there is not perfect methods, and the electronic structure we typically have to deal with is always approximate. The main purpose of this article, is to show how this, sometimes very limited information about the electronic structure extracted from the conventional calculations can be used for the solution of several practical questions, accumulated in the field of magnetism of the transition-metal oxides. This point will be illustrated for colossal-magnetoresistive manganites, double perovskites, and magnetic pyrochlores. We will review both successes and traps existing in the first-principle electronic structure calculations, and make connections with the models which capture the basic physics of the considered compounds. Particularly, we will show what kind of problems can be solved by adding the Hubbard U term on the top of the LSDA description. It is by no means a panacea from all existing problems of LSDA, and one should clearly distinguish the cases when U is indeed indispensable, play a minor role, or may even lead to the systematic error.

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confidence: 85%

Magnetic Interactions in Transition‐Metal Oxides

Solovyev

2003

ChemInform

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“…Due to the promising application of the CMR effect at room temperature, efforts have been made to investigate Ca 2 FeMoO 6 , Ba 2 FeMoO 2 and Sr 2−x Ba x MoO 6 , which have a structure similar to that of Sr 2 FeMoO 6 [3,4]. Sr 2 FeMoO 6 consists of FeO 6 and MoO 6 octahedra arranged alternately in the lattice, forming an ordered double perovskite structure. Band structure calculations [1,5] predict that Sr 2 FeMoO 6 has a half-metallic band structure where the conduction electrons are highly spin polarized even at room temperature.…”

Section: Introductionmentioning

confidence: 99%

Structural stability and electrical properties of Sr2Fe1+Mo1−O6− under high pressure

Zhang

et al. 2004

Journal of Alloys and Compounds

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“…In experiments done by both Kobayashi et al [12] and Sarma et al [13] a larger degree of B-B´ ordering was observed in the heavily tungsten doped compounds. However, no such ordering is observed on the B´ site for the W and Mo species, which remain randomly mixed.…”

Section: Ordering In Ternary B-b´-b´´ Systemsmentioning

confidence: 88%

Order-disorder transitions: structural and magnetic ordering in double perovskites

2010

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Using an effective lattice gas-like model for B-B' site ordering we study order-disorder transitions in double perovskite materials A 2 BB'O 6 . We motivate this effective model from a microscopic hamiltonian. Using this model, we are able to address several experimentally observed issues including nonmonotonic dependence of the degree of order on annealing temperature, and the rapid decrease of order upon overdoping with either B or B' species. We also study ordering in the 'ternary' compounds A 2 BB' 1-y B'' y O 6 , using a variant of the BlumeEmery-Griffiths model. Several issues related to structural and magnetic ordering are discussed.

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Possible percolation and magnetoresistance in ordered double perovskite alloys Sr2Fe(W1−xMox)O6

Cited by 109 publications

References 19 publications

Magnetic Interactions in Transition‐Metal Oxides

Magnetic Interactions in Transition‐Metal Oxides

Structural stability and electrical properties of Sr2Fe1+Mo1−O6− under high pressure

Order-disorder transitions: structural and magnetic ordering in double perovskites

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