SITE-SELECTIVE OXYGEN-ISOTOPE EFFECT, IN OPTIMALLY DOPED YBA2CU3O6+X

ZECH, D; KELLER, H; CONDER, K; KALDIS, E; LIAROKAPIS, E; POULAKIS, N; MULLER, KA

dc.contributor.author	ZECH, D	en
dc.contributor.author	KELLER, H	en
dc.contributor.author	CONDER, K	en
dc.contributor.author	KALDIS, E	en
dc.contributor.author	LIAROKAPIS, E	en
dc.contributor.author	POULAKIS, N	en
dc.contributor.author	MULLER, KA	en
dc.date.accessioned	2014-03-01T01:42:56Z
dc.date.available	2014-03-01T01:42:56Z
dc.date.issued	1994	en
dc.identifier.issn	0028-0836	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/23990
dc.subject.classification	Multidisciplinary Sciences	en
dc.subject.other	HIGH-TC SUPERCONDUCTORS	en
dc.subject.other	HIGH-TEMPERATURE SUPERCONDUCTIVITY	en
dc.subject.other	BA-CU-O	en
dc.subject.other	SHIFT	en
dc.subject.other	LA2-XSRXCUO4	en
dc.subject.other	SUBSTITUTION	en
dc.title	SITE-SELECTIVE OXYGEN-ISOTOPE EFFECT, IN OPTIMALLY DOPED YBA2CU3O6+X	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	1994	en
heal.abstract	IN CONVENTIONAL superconductors, the large dependence of the superconducting transition temperature (T-c) on the isotope mass (T-c proportional to m(-alpha), with alpha approximate to 0.5) gives strong evidence for electron pairing by a phonon-mediated mechanism. The copper oxide superconductors, on the other hand, exhibit a small oxygen isotope effect (alpha approximate to 0.02; see, for example, refs 1-14), suggesting a mechanism more complex than simple phonon-mediated pairing(15). To obtain further insight into this mechanism, it is important to determine the contribution from different oxygen sites in the crystal lattice to the total oxygen isotope effect. Recently, a negative isotope effect associated with oxygen atoms in the copper oxide planes of the crystal structure was reported(13) for highly doped YBa2Cu3O6+x, implying that the apical/chain oxygens make a substantial contribution to the total oxygen isotope shift. Here we investigate this effect in optimally doped YBa2Cu3O6+x, by measuring separately the contributions to the total isotope shift of the planar and apical/chain oxygen sites. The sum of the site-selective isotope shifts equals that of the total measured shift, illustrating the self-consistency of our results. In contrast to the previous Work(13), we find that more than 80% of the total (positive) isotope effect is associated with the copper oxide planes.	en
heal.publisher	MACMILLAN MAGAZINES LTD	en
heal.journalName	NATURE	en
dc.identifier.isi	ISI:A1994PM77300048	en
dc.identifier.volume	371	en
dc.identifier.issue	6499	en
dc.identifier.spage	681	en
dc.identifier.epage	683	en