Dependence of Tc on hydrostatic pressure in superconducting MgB2

T. Tomita; J. J. Hamlin; J. S. Schilling; D. G. Hinks; J. D. Jorgensen

doi:10.1103/PhysRevB.64.092505

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Dependence of Tc on hydrostatic pressure in superconducting MgB2

T. Tomita, J. J. Hamlin, J. S. Schilling, D. G. Hinks, J. D. Jorgensen

DOI 10.1103/PhysRevB.64.092505 · Physical Review B

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Abstract

The dependence of Tc on hydrostatic (He-gas) pressure for superconducting MgB2 has been determined to 0.7 GPa. We find that Tc decreases linearly and reversibly under pressure at the rate dTc/dP≃−1.11±0.02 K/GPa. These studies were carried out on the same sample used in earlier structural studies under He-gas pressure which yielded the bulk modulus B=147.2±0.7 GPa. The value of the logarithmic volume derivative of Tc is thus accurately determined, dlnTc/dlnV=+4.16±0.08, allowing quantitative comparison with theory. The present results support the emerging picture that MgB2 is a BCS superconductor with electron-phonon pairing interaction.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
MgB2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	39.25	Pressure unresolved	onset
MgB2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	38.88	0.341 GPa	onset
Pb Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
Sn Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	3.73	Pressure not reported	unknown