Oxidation and reduction of BaLa4Cu5O13+δ

Davies, Peter K.; Katzan, Cynthia M.

doi:10.1016/0022-4596(90)90231-l

Cited by 18 publications

(8 citation statements)

References 11 publications

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“…Three phases (tetragonal, orthorhombic, and monoclinic) are known for La 4 BaCu 5 O y , depending on the oxygen content y. [18][19][20] Since oxygen ions easily pass through the grain boundaries, different minor phases may be stabilized at the grain boundaries, which can affect the resistivity significantly. As we will see later, such a small fraction of the minor phases at the grain boundary does not affect the thermopower, 21 which is actually found in the thermopower measurement (see Fig.…”

Section: -2mentioning

confidence: 99%

An origin of good electrical conduction in La4BaCu5O13+δ

Mori

Asai

Terasaki

et al. 2015

Journal of Applied Physics

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We have prepared a set of polycrystalline samples of the metallic copper oxide La 4 BaCu 5Àx Co x O 13þd (0 x 0.35) and have measured the resistivity from 4 to 800 K. All the resistivities show metallic temperature dependence with a small magnitude less than 2 mX cm at 800 K, indicating that the metallic conduction is robust against impurities. The robust metallic conduction further suggests that this class of oxide is a promising candidate for electrical leads at high temperature, which might replace platinum. A detailed measurement and analysis on the Hall resistivity have revealed that at least two components are responsible for the electrical conduction, in which a large number of electrons of moderate mobility coexist with a much smaller number of holes of extremely high mobility. This large electron density well screens the impurity potential and retains the metallic conduction against 7% impurity doping. V C 2015 AIP Publishing LLC.

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Section: -2mentioning

confidence: 99%

An origin of good electrical conduction in La4BaCu5O13+δ

Mori

Asai

Terasaki

et al. 2015

Journal of Applied Physics

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“…However, when the oxygen content is varied in contact with a hydrogen-containing atmosphere at temperatures lower than 400~ the oxygen content can be further reduced (to w=-2.0) upon formation of structural variants with, inter alia, linear Cu(I) coordinations in the still intact matrix of metal atoms [426,427], e.g., BaLa4Cu5012 {P2/m; 890.1(2), 377.1(2), 869.1(2), 88.60(2)}. All these reduced compounds can be reoxidized into the oxygen saturated structure [426]. Thermodynamics of the oxygen-exchange reaction is investigated in Ref.…”

Section: Re=la the La(o)-ba(o)-cu(o) Phase Diagram At 950~ In Oxygenmentioning

confidence: 97%

“…At low oxygen partial pressures and high temperatures, the oxygen content can be varied between --0.5<w<0.16 without a bulk decomposition into Cu and La, Ba oxides [426]. However, when the oxygen content is varied in contact with a hydrogen-containing atmosphere at temperatures lower than 400~ the oxygen content can be further reduced (to w=-2.0) upon formation of structural variants with, inter alia, linear Cu(I) coordinations in the still intact matrix of metal atoms [426,427], e.g., BaLa4Cu5012 {P2/m; 890.1(2), 377.1(2), 869.1(2), 88.60(2)}. All these reduced compounds can be reoxidized into the oxygen saturated structure [426].…”

Section: Re=la the La(o)-ba(o)-cu(o) Phase Diagram At 950~ In Oxygenmentioning

confidence: 99%

“…The oxide is a metallic conductor but no superconductivity is reported. The oxygen saturated phase of tetragonal symmetry [425] has a rather high copper valence {BaLa4CusO]3.16; P4/m; 864.75(1), 385.94(1)} and the oxygen content decreases only slightly (-0.2 < w < 0.16) with tempera- ; e -BaLa4CusOl 3 [426] ture increasing up to 1015~ at ambient oxygen pressure [426]. At low oxygen partial pressures and high temperatures, the oxygen content can be varied between --0.5<w<0.16 without a bulk decomposition into Cu and La, Ba oxides [426].…”

Section: Re=la the La(o)-ba(o)-cu(o) Phase Diagram At 950~ In Oxygenmentioning

confidence: 99%

“…The oxygen saturated phase of tetragonal symmetry [425] has a rather high copper valence {BaLa4CusO]3.16; P4/m; 864.75(1), 385.94(1)} and the oxygen content decreases only slightly (-0.2 < w < 0.16) with tempera- ; e -BaLa4CusOl 3 [426] ture increasing up to 1015~ at ambient oxygen pressure [426]. At low oxygen partial pressures and high temperatures, the oxygen content can be varied between --0.5<w<0.16 without a bulk decomposition into Cu and La, Ba oxides [426]. However, when the oxygen content is varied in contact with a hydrogen-containing atmosphere at temperatures lower than 400~ the oxygen content can be further reduced (to w=-2.0) upon formation of structural variants with, inter alia, linear Cu(I) coordinations in the still intact matrix of metal atoms [426,427], e.g., BaLa4Cu5012 {P2/m; 890.1(2), 377.1(2), 869.1(2), 88.60(2)}.…”

Section: Re=la the La(o)-ba(o)-cu(o) Phase Diagram At 950~ In Oxygenmentioning

confidence: 99%

See 2 more Smart Citations

Phase diagrams for the YBa2Cu3O7 family — ANNO 1996

Karen

Kjekshus

1997

Journal of Thermal Analysis

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Phase diagrams for cupratcs of alkaline earth and rare earth elements are presented, covering binary to quintenary oxides and including selected solid solution series with other elements. Elementary crystal chemical data are included for identification of the occurring phases. Chemical stability is discussed with respect to the high-temperature reactions with Lewis acids like CO2, protons, etc. Particularly the occurrence of oxide carbonates is consistently pointed out as one of the possible reasons for contradictory results in phase diagrams which comprise oxides with high basicity.

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