@article{36fc8a503f2f42758a5d409b1f5f8ed9,
title = "Charge-distributions in YuPr1-uBa2Cu3Ox",
abstract = "The charge-distributions of YuPr1-uBa2Cu3Ox with x ≈ 7 are determined from the Rietveld-refined neutron scattering data of Neumeier et al. using the bond-valence-sum method. Differences between these charge distributions and those proposed by the Charge-Transfer hypothesis and the Fehrenbacher-Rice model are pointed out.",
author = "Blackstead, \{Howard A.\} and Dow, \{John D.\} and Federici, \{John F.\} and Packard, \{William E.\} and Pulling, \{David B.\}",
note = "Funding Information: Ba-O line has a slope of zero (it does, within experimentauln certainty)(;i ii) therei s an abrupt changeo f chargea t Uc, the insulating-superconducttrianng-sition composition(n o evidenceo f it); and (iv) holes transferf rom the chains to the planes as u increases and one proceedfsr om the insulatingto wardt he superconductinsgta te( the slope of the chain charge indicates that electrons transfern, ot holes). Particularlyd isturbingis the fact that the chains gain holes (not electrons) and the insulatings andwichegsa inelec-tronsa st hem ateriagl oesf romi nsulating to superconductinyge, t the p-type su-percondactiviitsy s upposedto originate in the initially insulatings andwiches whichh aveb eend opedn -type\textbackslash{}F[ urther-more, insulatingP rBa2Cu30x has al-mostt hes amel ayerc hargesa ndcharge-transferas s superconductin(fgo r x>6.4) YBa2Cu30x when the oxygenc ontent x is varied. Thus the Charge-Transfer hypothesisis invalid, being neither a necessarny or a sufficientc onditionf or YuPrl\_uBa2Cu3x0 superconductivity. Rare-earthio ns on rare-eartshi tesd o not break Cooper pairs, but a rare-eartho n a Ba-sited oes\textbackslash{} [2\textbackslash{}]B. a-siteo c-cupancyb y Pr in PrBa2Cu30x \textbackslash{}[5\textbackslash{}]i s signalledi n the neutrond ata by the presenceo f oxygena t an anitchains ite in a chain layer \textbackslash{}[1\textbackslash{}]a, nd is the key to the non-superconductcinhga racteorf PrBa2Cu3x0 \textbackslash{}[2\textbackslash{}]. Much of what we havee xtractefdr om the neutrond ata conflictsw ith the recent theory of Fehrenbachearn d Rice \textbackslash{}[81i,n cludingt he following: (i) Pr acts as a pair-breakerw hen on the Ba-site, but not on the rare-earths ite; (ii) the non-superconducticnhga racter of PrBa2Cu307 is instrinsic and related to Ba-site occupancy; (iii) the hole concentratiocno rrespondtso about 0.51eI per unit cell in the chains of YuPrl\_uBa2Cu3x0 and varies some with u; and (iv) Cu+3 is absent\textbackslash{}[ 4\textbackslash{}]. Clearly the Charge-Transfehry poth-esis and the Fehrenbacher-Ricmeo del both requirer evisionsw, ith perhapst he most importannt ew elemenbt eingt hat (Rare-earth)Ba2Cux3 s0u perconductiv-ity originatesin chain layers,w ith Ba-site pr+3 breakingC ooperp airs\textbackslash{}[4\textbackslash{}]. Acknowledgementms We thank the U.S. Officeo f Naval ResearchA, ir Force Office of Scientific Research,a nd De-partmenot f Energy for support( Contract Nos. N00014-92-J-1425A,F OSR-91-0418a, ndDE-FG02-90ER45427). Copyright: Copyright 2014 Elsevier B.V., All rights reserved.",
year = "1994",
month = dec,
doi = "10.1016/0921-4534(94)92302-7",
language = "English (US)",
volume = "235-240",
pages = "2161--2162",
journal = "Physica C: Superconductivity and its Applications",
issn = "0921-4534",
publisher = "Elsevier B.V.",
number = "PART 4",
}