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Pentcheva, Rossitza; Wendler, Frank; Meyerheim, H. L.; Moritz, Wolfgang; Jedrecy, N.; Scheffler, Matthias

doi:10.1103/physrevlett.94.126101

Cited by 194 publications

(172 citation statements)

References 21 publications

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“…1a). In this distorted bulk truncation (DBT) model, a Jahn-Teller distortion of the octahedrally coordinated iron ions in the surface leads to a wave-like displacement of the surface oxygen-iron rows [11,12], in qualitative agreement with contrast observed in STM images. LEED I-V and SXRD experiments were concluded to confirm the structure.…”

Section: Introductionsupporting

confidence: 61%

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Atomic structure and stability of magnetite Fe3O4(001): An X-ray view

et al. 2016

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Section: Introductionsupporting

confidence: 61%

“…Here we present an extended SXRD dataset from the √ 2 × √ 2R45 • surface in comparison to a previous SXRD study [11]. Structure factors extracted from the data were used to compare and refine the different models.…”

Section: Introductionmentioning

confidence: 99%

Atomic structure and stability of magnetite Fe3O4(001): An X-ray view

et al. 2016

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“…We note, however, that the bulk phase diagram of the FeO-Fe 3 O 4 -Fe 2 O 3 system 3 indicates stability of magnetite for much lower oxygen partial pressure than that taken in Ref. 25 as the "O-poor limit." Moreover, the short-range order of Fe͑A͒ and dimerization on the surface is not considered in the models of Refs.…”

Section: Resultsmentioning

confidence: 93%

“…8,13 A number of recent papers have tried to explain theoretically the structure of the ͑001͒ magnetite surface. [23][24][25] In particular, Pentcheva et al 25 explained the ͑ͱ2 ϫ ͱ 2͒R45°re-construction of the B-terminated surface in terms of the JahnTeller distortion. Our present calculations of the B termination agree well with this picture.…”

Section: Resultsmentioning

confidence: 99%

Fe3O4(001)films onFe(001): Termination and recons

et al. 2006

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“…Its (100) surface has been extensively studied. [3][4][5][6][7][8][9][10][11][12][13][14][15] Instead of the (1 × 1) bulklike termination, it reconstructs into a structure with a larger ( √ 2 × √ 2)R45 • unit cell. The atomic structure of this reconstruction has been painstakingly unraveled by density functional theory (DFT), low-energy electron diffraction (LEED), and scanning tunneling microscopy (STM) 4 -the surface is terminated by octahedrally coordinated iron atoms arranged in rows, as shown in Fig.…”

mentioning

confidence: 99%

Order-disorder phase transition on the (100) surface of magnetite

et al. 2013

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Using low-energy electron diffraction, we show that the room-temperature ( √ 2 × √ 2)R45 • reconstruction of Fe 3 O 4 (100) reversibly disorders at ∼450 • C. Short-range order persists above the transition, suggesting that the transition is second order and Ising-like. We interpret the transition in terms of a model in which subsurface Fe 3+ is replaced by Fe 2+ as the temperature is raised. This model reproduces the structure of antiphase boundaries previously observed with scanning tunneling microscopy, as well as the continuous nature of the transition. To account for the observed transition temperature, the energy cost of each charge rearrangement is 82 meV. Metal oxides are often useful because of their stability at high temperatures. An example is magnetite, Fe 3 O 4 . In catalytic applications such as the water-gas shift reaction, 1 magnetite is used at temperatures between 300 and 500 • C. Furthermore, magnetite's high Curie temperature of 580 • C allows spintronic applications. 2 Since such applications frequently depend on surface properties, a natural question arises-how does the surface structure change with temperature?The room-temperature properties of magnetite's surfaces are complex. Its (100) surface has been extensively studied. [3][4][5][6][7][8][9][10][11][12][13][14][15] Instead of the (1 × 1) bulklike termination, it reconstructs into a structure with a larger ( √ 2 × √ 2)R45 • unit cell. The atomic structure of this reconstruction has been painstakingly unraveled by density functional theory (DFT), low-energy electron diffraction (LEED), and scanning tunneling microscopy (STM) 4 -the surface is terminated by octahedrally coordinated iron atoms arranged in rows, as shown in Fig. 1(a). The observed periodicity results from small displacements of the iron atoms perpendicular to the rows [see Fig. 1(b)]. The driving force for the reconstruction is believed to be ordering of the charge state of the iron in octahedral sites beneath the surface. 15,16 In bulk magnetite at room temperature the average charge state of octahedral iron is +2.5e. The subsurface charge ordering involves disproportionation of this charge into more positively and negatively charged sites. It has been proposed 15,16 that the disproportionation is greatest in the plane of octahedral iron beneath the top layer. Figure 1(c) sketches the proposed charge order in this subsurface layer. In Fig. 1(c), and in our discussion below, the two charge states in the second layer are labeled by their nominal oxidation state Fe 3+ and Fe 2+ , although the charges are estimated to only differ by 0.2-0.4 e rather than e. 15,17 The top layer octahedral iron is displaced in the surface plane to decrease the distance to the nearest subsurface Fe 2+ , giving the undulating rows of surface octahedral iron observed by LEED and STM.What might happen to such a structure when the temperature is raised? One possibility is that the high-temperature, high-entropy surface differs significantly in stoichiometry and termination from the charge ordered ( √...

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Jahn-Teller Stabilization of a “Polar” Metal Oxide Surface:Fe3O4(001)

Cited by 194 publications

References 21 publications

Atomic structure and stability of magnetite Fe3O4(001): An X-ray view

Atomic structure and stability of magnetite Fe3O4(001): An X-ray view

Fe3O4(001)films onFe(001): Termination and recons

Order-disorder phase transition on the (100) surface of magnetite

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