From Carbonate-Cuprates to Cuprate-Carbonates: The Structural Equivalence of CO3and CuOxGroups in the Ba–Cu–C–O System

Matacotta, F.C.; Calestani, G.; Migliori, A.; Nozar, P.; Scardi, Paolo; Greco, Pierpaolo; Ricci, Pier Carlo; Tomasi, A.; Thomas, Kenneth A.

doi:10.1006/jssc.1996.7167

Cited by 8 publications

(6 citation statements)

References 16 publications

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“…The structure analysis by neutron powder diffraction revealed that CO 3 2+ group is located at the Cu chain site. As a result, a part of chain site oxygen was pushed out together with Cu, as is similar to the case of Ba(CuO x ) 1-y (CO 3 ) y (y < 0.5) [ 9 ]. It is noted that the lattice parameter, c, is remarkably shortened by carbonate substitution, accompanied with lowering orthorhmbicity.…”

supporting

confidence: 59%

Effects of carbon incorporation on doping state of YBa2Cu3Oy

Yamamoto

Hirose

Itoh

et al. 2005

Physica C: Superconductivity

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Effects of carbon incorporation on the doping state of YBa 2 Cu 3 O y (Y-123) were investigated.Quantitative carbon analysis revealed that carbon could be introduced into Y-123 from both the precursor and the sintering gas. Nearly carbon-free (< 200 ppm) samples were prepared from a vacuum-treated precursor by sintered at 900 ˚C and cooling with 20 ˚C /min in flowing oxygen gas. The lower T c (= 88 K) and higher oxygen content (y = 6.98) strongly suggested the overdoping state, which was supported by the temperature dependence of resisitivity and thermoelectric power. The nuclear quadrapole resonance spectra and the Raman scattering spectra indicated that there was almost no oxygen defect in the Cu-O chain in these samples.On the other hand, in the same cooling condition, the samples sintered in air stayed at optimal doping level with T c = 93 K, and the intentionally carbon-doped sample was in the underdoping state. It is revealed that about 60% of incorporated carbon was substituted for Cu at the chain site in the form of CO 3 2+ , and the rest remains at the grain boundary as carbonate impurities. Such incorporation affected the oxygen absorption process in Y-123. It turned out that the oxygen content in Y-123 cannot be controlled only by the annealing temperature and the oxygen partial pressure but also by the incorporated carbon concentration.

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supporting

confidence: 59%

Effects of carbon incorporation on doping state of YBa2Cu3Oy

Yamamoto

Hirose

Itoh

et al. 2005

Physica C: Superconductivity

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“…2Ϫ into CuO ␦ chains in Ba-based superconducting cuprate structures, 23 was recently shown to result in a solid solution of carbonate and cuprate groups even in BaCO 3 up to the stoichiometry of Ba͑CO 3 ͒ 0.5 ͑CuO ␦ ͒ 0.5 . 24 In the present study, however, the carbonate contamination was found to be negligible, since both the coulometric titration and H 2 /TG reduction analyses gave within the estimated error limits the same values for the oxygen excess, i.e., ⑀ϭ0.13 and 0.06 for the oxidized and reduced BaCuO 2ϩ⑀ precursors, respectively. In Fig.…”

Section: Resultssupporting

confidence: 49%

Establishment of strongly overdoped states in theHgBa2Ca2Cu3
Fujinami
¹
,
Itô
²
,
Suematsu
³

et al. 1997
Phys. Rev. B
22
0
6
0
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Strongly overdoped HgBa 2 Ca 2 Cu 3 O 8ϩ␦ ͑Hg-1223͒ samples with superconducting transitions as low as 97 K were successfully obtained by using HgO, Ca 2 CuO 3 , CuO, and mixtures of highly oxidized BaCuO 2ϩ⑀ (⑀ Ϸ0.13) and/or BaO 2 powders as starting materials for the high-pressure synthesis at 5 GPa and 950°C. The overdoped state was confirmed by observing negative values for the Seebeck coefficient throughout the temperature range from T c to 320 K in a thermoelectric power measurement. Also, both of the cell parameters a and c were found to decrease with decreasing T c , reflecting, respectively, an increase in hole concentration in the CuO 2 planes and the incorporation of oxygen into the HgO ␦ layer. The oxygen excess ␦ as determined by the Cu͑ϩI͒/Cu͑ϩII͒ coulometric titration method, was ϳ0.19 in the overdoped sample with T c ϭ107 K. Subsequent reducing annealing in an Ar atmosphere at 280°C increased the T c to 131 K. Consistently, only positive Seebeck coefficient values were observed up to 320 K for the Ar-annealed sample. A clearly underdoped material with T c ϭ118 K was obtained by annealing the same sample in Ar at a higher temperature (ϳ400°C). Finally, high-pressure synthesis starting from less-oxidized BaCuO 2ϩ⑀ (⑀Ϸ0.06) yielded a Hg-1223 material with ␦Ϸ0.10 and T c ϭ132 K. ͓S0163-1829͑97͒04945-X͔

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“…This is not wholly unprecedented -copper, another d-block transition metal, can be incorporated into witherite as an oxidized cuprate without creating a new phase. 27 The material produced by our hydrothermal process is crystalline with a minimally distorted crystal structure. It can be described as a form of manganese-doped witherite (MDW).…”

Section: Resultsmentioning

confidence: 99%

A Manganese-Doped Barium Carbonate Cathode for Alkaline Batteries

Hertzberg

Sviridov

Stach

et al. 2014

J. Electrochem. Soc.

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MnO2-Zn alkaline batteries are one of the most common modern forms of primary battery, due to their relatively high energy density and low cost per kilowatt-hour. Additionally, unlike many other types of primary battery, alkaline cells can theoretically be recharged. Their low cost per kilowatt-hour makes them potentially ideal for applications such as sustainable energy storage or peak demand shaving. However, a phase transformation that occurs in MnO2 after reduction by more than one electron converts it into the electrochemically inactive Mn3O4 phase. This limits the total depth of discharge of the cell significantly. We report the synthesis of a novel electrode material, manganese-doped witherite, for rechargeable alkaline batteries produced by a simple hydrothermal process. The material has been studied via X-ray diffraction and electroanalytical techniques. We show that unaltered witherite has poor electrochemical properties, and that this new material has high capacity and rate capability, even under deep discharge conditions, superior to conventional manganese dioxide.

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From Carbonate-Cuprates to Cuprate-Carbonates: The Structural Equivalence of CO3and CuOxGroups in the Ba–Cu–C–O System

Cited by 8 publications

References 16 publications

Effects of carbon incorporation on doping state of YBa2Cu3Oy

Effects of carbon incorporation on doping state of YBa2Cu3Oy

Establishment of strongly overdoped states in theHgBa2Ca2Cu3
Fujinami
¹
,
Itô
²
,
Suematsu
³

et al. 1997
Phys. Rev. B
22
0
6
0
View full text Add to dashboard Cite

A Manganese-Doped Barium Carbonate Cathode for Alkaline Batteries

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From Carbonate-Cuprates to Cuprate-Carbonates: The Structural Equivalence of CO3and CuOxGroups in the Ba–Cu–C–O System

Cited by 8 publications

References 16 publications

Effects of carbon incorporation on doping state of YBa2Cu3Oy

Effects of carbon incorporation on doping state of YBa2Cu3Oy

Establishment of strongly overdoped states in theHgBa2Ca2Cu3Fujinami1, Itô2, Suematsu3 et al. 1997Phys. Rev. B22060View full textAdd to dashboardCite

A Manganese-Doped Barium Carbonate Cathode for Alkaline Batteries

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Product

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About

Establishment of strongly overdoped states in theHgBa2Ca2Cu3
Fujinami
¹
,
Itô
²
,
Suematsu
³

et al. 1997
Phys. Rev. B
22
0
6
0
View full text Add to dashboard Cite