Specific heat of Bi2Sr2CuO6 and Bi2Sr2CaCu2O8 in the superconducting state
A. Chakraborty, A. J. Epstein, D. L. Cox, E. M. McCarron, W. E. Farneth
DOI 10.1103/PhysRevB.39.12267 · Physical Review B
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
We have measured the specific heat C(T) of single-phase samples of the cuprate superconductors Bi2Sr2CuO6−δ (2:2:0:1; Tc=12.5 K) and Bi2Sr2CaCu2O8−δ (2:2:1:2; Tc=84 K) in the temperature range 3-11 K. Bulk superconductivity with a Meissner fraction of about 25% is observed for both materials. We find no strong evidence for a term in C(T) linear in the temperature T; rather, C(T)T is a linear function of T2 in this temperature range. A least-squares fit gives an upper bound of 0.35 mJ/CuK2 for any linear term. This result appears to rule out gapless pairing and gap functions with lines of nodes in these materials. Though gap functions with point nodes are not excluded by our results, we demonstrate that possibility to be unlikely in these materials. We suggest further experiments to test whether such T3 electronic contribution to the specific heat exists for the 2:2:0:1 material.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| Bi2Sr2CuO6-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 12.5 | Pressure not reported | unknown |
| Bi2Sr2CaCu2O8-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 84 | Pressure not reported | unknown |
| La2-xBaxCuO4-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
| YBa2Cu3O7-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
Similar papers
Thermal conductivity of Bi-Sr-Ca-Cu-O superconductors: Correlation with the low-temperature specific-heat behavior
similarity 0.97S. D. Peacor & C. Uher
Source status unknown — claims are unverified
Superconductivity fluctuation effects on the thermal conductivity of Bi2Sr2CaCu2O8
similarity 0.97M. Houssa et al.
Source status unknown — claims are unverified
Crystallographic, thermodynamic, and transport properties of the Bi2Sr3−xCaxCu2O8+δ superconductor
similarity 0.96G. S. Grader et al.
Source status unknown — claims are unverified
Thermal conductivity of superconducting Bi2Sr2CaCu2O8 and YBa2Cu3O7−y
similarity 0.96M. Houssa & M. Ausloos
Source status unknown — claims are unverified
Investigation of the superconducting order parameter in Bi2Sr2CaCu2O8 single crystals
similarity 0.96T. Staufer et al.
Source status unknown — claims are unverified
Specific-heat anomaly near Tc of the (Bi,Pb)-Sr-Ca-Cu-O superconductor (Tc=107 K)
similarity 0.95N. Okazaki et al.
Source status unknown — claims are unverified