Structural defects in YBa2Cu2CoO6+x and YBaCuCoO5

Jacob, Michael; Hansen, Staffan; Sturefelt, Sten

doi:10.1051/mmm:0199000105-6031900

Cited by 8 publications

(5 citation statements)

References 19 publications

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“…The perovskite-related compound YBaCo 2 O 5 was first reported by Zhou et al in 1993, and its structure was determined using powder X-ray diffraction (XRD), selected area electron diffraction (SAED), and high-resolution transmission electron microscopy (HRTEM). YBaCo 2 O 5 is isomorphous with other previously reported compounds such as YBaCuCoO 5 and YBaCuFeO 5 with the basic structure as shown in Figure a. Its structure can be regarded as a derivative of the high- T c superconducting compound YBa 2 Cu 3 O 7 by removing one Ba−O layer and the Cu−O chain originally sandwiched by two Ba−O layers with the remaining copper cations being substituted by the cobalt cations.…”

Section: Introductionmentioning

confidence: 71%

Structural Chemistry and Conductivity of a Solid Solution of YBa_1-_xSr_xCo₂O₅₊_δ

et al. 2007

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Solid solution specimens of YBa1- x Sr x Co2O5+ δ (0 ≤ x ≤ 1) were prepared by solid−solid reactions. The structures were initially investigated using powder X-ray diffraction and further studied using selected area electron diffraction and high-resolution transmission electron microscopy. A 3 × 3 × 1 superstructure derived from oxygen ordering up to 30% Sr doping has been identified. In the Sr-rich compositions, a √2 × √2 × 1 superstructure formed due to lattice distortion. The formation mechanisms of these two superstructures and the relation between the unit cell dimensions and the Sr content were discussed. The conductivity of some selected compositions was also measured with a maximum in conductivity in the range 180−320 °C, indicating a form of metal to insulator transition at this temperature that is unlikely to be related to a major change in oxygen content.

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Section: Introductionmentioning

confidence: 71%

Structural Chemistry and Conductivity of a Solid Solution of YBa_1-_xSr_xCo₂O₅₊_δ

et al. 2007

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“…The R BaFe 2 O 5 oxides crystallize as double-cell perovskites (Figure ) analogous to the prototype YBaCuFeO 5 . Other variants of this structure type include combinations such as Mn and Co, Fe and Co, Co and Cu (but none involving Ni), as well as R BaMn 2 O 5 , and R BaCo 2 O 5 phases. The size difference between R 3+ and Ba 2+ stabilizes layered ordering of both cations and oxygen vacancies.…”

Section: Introductionmentioning

confidence: 97%

Structural Tuning of Charge, Orbital, and Spin Ordering in Double-Cell Perovskite Series between NdBaFe₂O₅ and HoBaFe₂O₅

2003

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Charge, orbital, and magnetic ordering of NdBaFe(2)O(5) and HoBaFe(2)O(5), the two end-members of the double-cell perovskite series RBaFe(2)O(5), have been characterized over the temperature range 2-450 K, using differential scanning calorimetry, neutron thermodiffractometry and high-resolution neutron powder diffraction. Upon cooling, both compounds transform from a class-III mixed valence (MV) compound, where all iron atoms exist as equivalent MV Fe(2.5+) ions, through a "premonitory" charge ordering into a class-II MV compound, and finally to a class-I MV phase at low-temperature. The latter phase is characterized by Fe(2+)/Fe(3+) charge ordering as well as orbital ordering of the doubly occupied Fe(2+) d(xz) orbitals. The relative simplicity of the crystal and magnetic structure of the low-temperature charge-ordered state provide an unusual opportunity to fully characterize the classical Verwey transition, first observed in magnetite, Fe(3)O(4). Despite isotypism of the title compounds at high temperature, neutron diffraction analysis reveals striking differences in their phase transitions. In HoBaFe(2)O(5), the Verwey transition is accompanied by a reversal of the direct Fe-Fe magnetic coupling across the rare earth layer, from ferromagnetic in the class-II and -III MV phases to antiferromagnetic in the low-temperature class-I MV phase. In NdBaFe(2)O(5), the larger Nd(3+) ion increases the Fe-Fe distance, thereby weakening the Fe-Fe magnetic interaction. This decouples the charge and magnetic ordering so that the Fe-Fe interaction remains ferromagnetic to low temperature. Furthermore, the symmetry of the charge-ordered class-I MV phase is reduced from Pmma to P2(1)()ma and the magnitude of the orbital ordering is diminished. These changes destabilize the charge-ordered state and suppress the temperature at which the Verwey transition occurs. A comparison of the magnetic and structural features of RBaFe(2)O(5) compounds is included in order to illustrate how structural tuning, via changes in the radius of the rare-earth ion, can be used to alter the physical properties of these double-cell perovskites.

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“…In this way, the first “112” structure was discovered for the oxide YBaCuFeO 5 (Figure a). The possibility, to introduce trivalent cobalt was shown two years later with the synthesis of the isostructural oxide YBaCuCoO 5 . The ability of this system to accommodate higher cobalt contents and its properties to absorb oxygen, keeping the 112‐type structure with the mixed valence Co(II)/Co(III), was evidenced for the first time in 1992 for the oxides YBaCo 2‐x Cu x O 5+δ , with x values comprised between 0.3 and 1 and δ ranging from 0 to 0.25 .…”

Section: The “112” Lnbam2o5 Oxygen Deficient Ordered Perovskites (M=cmentioning

confidence: 99%

Introducing Barium in Transition Metal Oxide Frameworks: Impact upon Superconductivity, Magnetism, Multiferroism and Oxygen Diffusion and Storage

Raveau

2016

The Chemical Record

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Structural defects in YBa2Cu2CoO6+x and YBaCuCoO5

Cited by 8 publications

References 19 publications

Structural Chemistry and Conductivity of a Solid Solution of YBa_1-_xSr_xCo₂O₅₊_δ

Structural Chemistry and Conductivity of a Solid Solution of YBa_1-_xSr_xCo₂O₅₊_δ

Structural Tuning of Charge, Orbital, and Spin Ordering in Double-Cell Perovskite Series between NdBaFe₂O₅ and HoBaFe₂O₅

Introducing Barium in Transition Metal Oxide Frameworks: Impact upon Superconductivity, Magnetism, Multiferroism and Oxygen Diffusion and Storage

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Structural defects in YBa2Cu2CoO6+x and YBaCuCoO5

Cited by 8 publications

References 19 publications

Structural Chemistry and Conductivity of a Solid Solution of YBa1-xSrxCo2O5+δ

Structural Chemistry and Conductivity of a Solid Solution of YBa1-xSrxCo2O5+δ

Structural Tuning of Charge, Orbital, and Spin Ordering in Double-Cell Perovskite Series between NdBaFe2O5 and HoBaFe2O5

Introducing Barium in Transition Metal Oxide Frameworks: Impact upon Superconductivity, Magnetism, Multiferroism and Oxygen Diffusion and Storage

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Structural Chemistry and Conductivity of a Solid Solution of YBa_1-_xSr_xCo₂O₅₊_δ

Structural Chemistry and Conductivity of a Solid Solution of YBa_1-_xSr_xCo₂O₅₊_δ

Structural Tuning of Charge, Orbital, and Spin Ordering in Double-Cell Perovskite Series between NdBaFe₂O₅ and HoBaFe₂O₅