Synthesis and Properties of YBaMn2O5+δ

Beales, T.P.; Mölgg, M.; Jutson, J.A.; Friend, C.M.

doi:10.1002/1521-396x(199705)161:1<271::aid-pssa271>3.0.co;2-2

Cited by 24 publications

(10 citation statements)

References 19 publications

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“…The synthesis of the ordered perovskite requires several complex processes as described in Refs. [7] and [8]. Starting materials Y 2 O 3 , MnO 2 , and BaCO 3 were ground thoroughly, pressed into pellets and calcined in an Ar flow at 1300 °C for 48 h which yields the ordered YBaMn 2 O 6-y (y~0.9) with a large amount of oxygen vacancy in the YO layer.…”

Section: Methodsmentioning

confidence: 99%

Successive phase transitions in a metal-ordered manganite perovskite YBaMn2O6

Nakajima

Kageyama

Ueda

2002

Journal of Physics and Chemistry of Solids

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Section: Methodsmentioning

confidence: 99%

Successive phase transitions in a metal-ordered manganite perovskite YBaMn2O6

Nakajima

Kageyama

Ueda

2002

Journal of Physics and Chemistry of Solids

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“…As previously reported, the synthesis of the double perovskite oxide YBaMn 2 O 5 þ δ must be carried out in a low oxygen partial pressure to prevent the formation of BaMnO 3 À δ [45][46][47][48][49]. Polycrystalline YBaMn 2 O 5 þ δ was synthesized via a solid state reaction under a mixture of dry N 2 and a water-saturated 5% H 2 /95% Ar gas mixture (pO 2 E10 À 12 atm).…”

Section: Synthesismentioning

confidence: 99%

A determination of the oxygen non-stoichiometry of the oxygen storage material YBaMn2O5+

Jeamjumnunja

Gong

Makarenko

et al. 2015

Journal of Solid State Chemistry

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Keywords:Oxygen storage material Double perovskite oxide Yttrium barium manganese oxide Oxygen non-stoichiometry a b s t r a c tThe A-site ordered double-perovskite oxide, YBaMn 2 O 5 þ δ , has been of recent interest for possible application as an oxygen storage material. In the present study, the oxygen non-stoichiometry of YBaMn 2 O 5 þ δ has been determined as a function of pO 2 at 650, 700 and 750°C by Coulometric titration at near-equilibrium conditions. The results confirm that this perovskite oxide has three distinct phases on oxidation/reduction with δE0, 0.5 and 1. The stabilities of the YBaMn 2 O 5 þ δ phases span a wide range of oxygen partial pressures (∼10 À 20 rpO 2 (atm) r ∼1 ) depending on temperature. The phases interconvert at higher pO 2 values at higher temperatures. The partial molar free energies (Δμ O ) corresponding to the oxidation of YBaMn 2 O 5 to YBaMn 2 O 5.5 and of YBaMn 2 O 5.5 to YBaMn 2 O ∼6 were determined. The value of Δμ O in both oxidation steps becomes less negative with increasing temperature. At some T and pO 2 conditions, YBaMn 2 O 5 þ δ is unstable with respect to decomposition to BaMnO 3 À δ and YMnO 3 . This instability is anticipated from the previous studies of the synthesis of YBaMn 2 O 5 þ δ but is more apparent in the present experiments which are necessarily slow in order to achieve equilibrium with respect to the oxygen content.

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“…The experimental studies also show semiconducting behavior. 12,35 From Table I it can be seen that the Ferri configuration has lower energy than the other two configurations. The present observation of the stabilization of a Ferri ground state in YBaMn 2 O 5 is consistent with the established magnetic structure.…”

Section: B Dos Characteristicsmentioning

confidence: 99%

Spin, charge, and orbital ordering in the ferrimagnetic insulatorYBaMn2O5

2002

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The oxygen-deficient ͑double͒ perovskite YBaMn 2 O 5 , containing corner-linked MnO 5 square pyramids, is found to exhibit ferrimagnetic ordering in its ground state. In the present work we report generalized-gradientcorrected, relativistic first-principles full-potential density-functional calculations performed on YBaMn 2 O 5 in the paramagnetic, ferromagnetic, and ferrimagnetic states. The charge, orbital, and spin orderings are explained with site-, spin-, angular-momentum-, and orbital-projected density of states, charge-density plots, electronic structure, and total energy studies. YBaMn 2 O 5 is found to stabilize in a G-type ferrimagnetic state in accordance with experimental results. The experimentally observed semiconducting behavior appears only when we include ferrimagnetic ordering in our calculation. We observed significant optical anisotropy in this material originating from the combined effect of ferrimagnetic ordering and crystal-field splitting. In order to gain knowledge about the presence of different valence states for Mn in YBaMn 2 O 5 we have calculated K-edge x-ray absorption near-edge spectra for the Mn and O atoms. The presence of the different valence states for Mn is clearly established from the x-ray absorption near-edge spectra, hyperfine field parameters, and the magnetic properties study. Among the experimentally proposed structures, the recently reported description based on P4/nmm is found to represent the stable structure.

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Synthesis and Properties of YBaMn2O5+δ

Cited by 24 publications

References 19 publications

Successive phase transitions in a metal-ordered manganite perovskite YBaMn2O6

Successive phase transitions in a metal-ordered manganite perovskite YBaMn2O6

A determination of the oxygen non-stoichiometry of the oxygen storage material YBaMn2O5+

Spin, charge, and orbital ordering in the ferrimagnetic insulatorYBaMn2O5

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