NMR evidence for common superconducting and pseudogap phase diagrams of YBa2Cu3O7−δ and La2−xSrxCaCu2O6

G. V. M. Williams; J. L. Tallon; R. Michalak; R. Dupree

doi:10.1103/PhysRevB.54.R6909

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NMR evidence for common superconducting and pseudogap phase diagrams of YBa2Cu3O7−δ and La2−xSrxCaCu2O6

G. V. M. Williams, J. L. Tallon, R. Michalak, R. Dupree

DOI 10.1103/PhysRevB.54.R6909 · Physical Review B

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Abstract

We report ac susceptibility and O17 nuclear-magnetic-resonance (NMR) measurements on the double-CuO2-layer La2−xSrxCaCu2O6 high-temperature superconducting cuprate (HTSC) with a Tc,max of 60 K. A comparison is made with Y89 NMR measurements on YBa2Cu3O7−δ, which has a higher Tc,max of 93 K and Y0.8Ca0.2Ba2Cu3O7−δ with a slightly lower Tc,max of 87 K. We find that the hole concentration dependence of the normal-state gap and of Tc both scale with Tc,max, implying a universal scaled phase diagram for these two superconductors, and, by implication, for the wider class of HTSC. This suggests that the normal-state gap and the pairing mechanism may have a common origin.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
La2-xSrxCaCu2O6 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	60	Pressure not reported	unknown
YBa2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	93	Pressure not reported	unknown
Y0.8Ca0.2Ba2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	87	Pressure not reported	unknown
La1.88Sr0.12CaCu2O6 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	12.7	Pressure not reported	onset
La1.84Sr0.16CaCu2O6 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	31.5	Pressure not reported	onset
La1.78Sr0.22CaCu2O6 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	47	Pressure not reported	onset
Y0.8Ca0.2Ba2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	47.5	Pressure not reported	unknown
Y0.8Ca0.2Ba2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	65.8	Pressure not reported	unknown
Y0.8Ca0.2Ba2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	83.2	Pressure not reported	unknown
Y0.8Ca0.2Ba2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	86	Pressure not reported	unknown
Y2Ba4Cu7O15 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	95	Pressure not reported	unknown
YBa2Cu4O8 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown