Doping dependence of the oxygen isotope effect in YBa2Cu3Ox

Zech, D.; Conder, K.; Keller, H.; Kaldis, E.; Müller, K. A.

doi:10.1016/0921-4526(95)00674-5

Cited by 33 publications

(35 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The oxygen isotope effect of T c has been observed in a number of experiments [71,57,56,72,73]. Here we discuss the results obtained on Pr-doped and oxygen-depleted YBa 2 Cu 3 O 7−δ (YPrBCO and YBCO respectively).…”

Section: Oxygen Isotope Effect In High-t C Materialsmentioning

confidence: 83%

See 1 more Smart Citation

The Isotope Effect in Superconductors

Bill

Kresin

Wolf

1998

Pair Correlations in Many-Fermion Systems

View full text Add to dashboard Cite

We review some aspects of the isotope effect (IE) in superconductors. Our focus is on the influence of factors not related to the pairing mechanism. After summarizing the main results obtained for conventional superconductors, we review the effect of magnetic impurities, the proximity effect and non-adiabaticity on the value of the isotope coefficient (IC). We discuss the isotope effect of T c and of the penetration depth δ. The theory is applied to conventional and high-T c superconductors. Experimental results obtained for YBa 2 Cu 3 O 7−δ related materials (Zn and Pr-substituted as well as oxygen-depleted systems) and for La 2−x Sr x CuO 4 are discussed.

show abstract

Section: Oxygen Isotope Effect In High-t C Materialsmentioning

confidence: 83%

“…Fig. 2 displays the experimental results obtained for the oxygen isotope coefficient of Zn-doped YBCO [56,4] (normalized to α 0 ≃ 0.025 [57]). One can see from this figure that the agreement between the theoretical dependence α(T c ) and the experiment is very good.…”

Section: Zn-doped Ybamentioning

confidence: 99%

The Isotope Effect in Superconductors

Bill

Kresin

Wolf

1998

Pair Correlations in Many-Fermion Systems

View full text Add to dashboard Cite

show abstract

“…As the material goes away from the optimal doping level, ␣ increases with decreasing T c . By changing the oxygen content, Zech et al (8) observed that ␣ remains rather small at T c Ӎ 61 K and then increases for a further decrease of T c down to Ϸ53 K in YBa 2 Cu 3 O 7Ϫ␦ (0.47 Ͼ ␦ Ͼ 0.01). The gradual increase of ␣ with the dramatic reduction of T c was reported in YBa 2 (Cu 1Ϫx Zn x ) 3 O 7Ϫ␦ (7).…”

Section: [3]mentioning

confidence: 99%

“…However, later experiments have revealed a much richer and more complex situation (7). There is a striking variation of ␣ with doping level in a given cuprate material (8)(9)(10)(11). Meanwhile, ␣ also varies among various compounds of different cuprate families (7,12).…”

mentioning

confidence: 99%

Unified picture of the oxygen isotope effect in cuprate superconductors

Chen

Struzhkin

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

High-temperature superconductivity in cuprates was discovered almost exactly 20 years ago, but a satisfactory theoretical explanation for this phenomenon is still lacking. The isotope effect has played an important role in establishing electron-phonon interaction as the dominant interaction in conventional superconductors. Here we present a unified picture of the oxygen isotope effect in cuprate superconductors based on a phonon-mediated d-wave pairing model within the Bardeen-Cooper-Schrieffer theory. We show that this model accounts for the magnitude of the isotope exponent as functions of the doping level as well as the variation between different cuprate superconductors. The isotope effect on the superconducting transition is also found to resemble the effect of pressure on the transition. These results indicate that the role of phonons should not be overlooked for explaining the superconductivity in cuprates.electron-phonon interaction ͉ high-temperature superconductivity ͉ pressure effect U nderstanding the high-temperature superconductivity in cuprate superconductors is at the heart of current research in solid-state physics. The isotope effect is an important experimental probe in revealing the underlying pairing mechanism of superconductivity. Early measurements (1) of the isotope effect on the superconducting transition temperature, T c , provided key experimental evidence for phonon-mediated pairing and supported strongly the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity in conventional materials. When hightemperature superconductivity was discovered in copper oxides, the oxygen isotope exponents, defined by ␣ ' ϪdlnT c /dlnM, with M being the isotopic mass, were promptly measured. The initial finding of the small value of ␣ in La 1.85 Sr 0.15 CuO 4 (2, 3) and near zero value in YBa 2 Cu 3 O 7Ϫ␦ (␦ ϳ 0) (4-6) was taken to be convincing evidence against electron-phonon interaction as the dominant mechanism in these materials. However, later experiments have revealed a much richer and more complex situation (7). There is a striking variation of ␣ with doping level in a given cuprate material (8-11). Meanwhile, ␣ also varies among various compounds of different cuprate families (7,12). Interestingly, ␣ is a remarkably monotonic function of the number of CuO 2 layers in a way opposite to T c in optimally doped compounds (12). Such elaborate isotope effects strongly suggest that one should include phonons in the theory of high-T c superconductivity. Studies of neutron scattering (13), angleresolved photoemission spectroscopy (14, 15), and scanning transmission electron microscopy (16) provide further evidence for phonons being an important player in the basic physics of high-T c superconductivity.Compared with isotope substitution, pressure has been realized not only to be another effective way to change T c for a superconductor (17) but also to yield information on the interaction causing the superconductivity. So far, the record high T c of 164 K was achieved under high pressure in HgBa 2 C...

show abstract

“…The small OIS observed in the optimally doped cuprates suggest that phonons might not be important in bringing about high temperature superconductivity. However, the doping dependence of the OIS has been extensively studied in different cuprate systems [17,[20][21][22][23][24][25][26][27]. For a particular family of doped cuprates the OIS increases with decreasing T c , and can be even larger than the BCS value.…”

Section: Isotope Effect On the Superconducting Transition Temperamentioning

confidence: 99%

Unconventional isotope effects in the high-temperature cuprate superconductors

Zhao

Keller

Conder

2001

J. Phys.: Condens. Matter

139

View full text Add to dashboard Cite

We review various isotope effects in the high-Tc cuprate superconductors to assess the role of the electron-phonon interaction in the basic physics of these materials. Of particular interest are the unconventional isotope effects on the supercarrier mass, on the charge-stripe formation temperature, on the pseudogap formation temperature, on the EPR linewidth, on the spin-glass freezing temperature, and on the antiferromagnetic ordering temperature. The observed unconventional isotope effects strongly suggest that lattice vibrations play an important role in the microscopic pairing mechanism of high-temperature superconductivity.

show abstract

Doping dependence of the oxygen isotope effect in YBa2Cu3Ox

Cited by 33 publications

References 12 publications

The Isotope Effect in Superconductors

The Isotope Effect in Superconductors

Unified picture of the oxygen isotope effect in cuprate superconductors

Unconventional isotope effects in the high-temperature cuprate superconductors

Contact Info

Product

Resources

About