The dependence of Tc on hydrostatic (He-gas) pressure 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.
@article{arxiv.cond-mat/0103538,
title = {The Dependence of Tc on Hydrostatic Pressure in Superconducting MgB2},
author = {T. Tomita and J. J. Hamlin and J. S. Schilling and D. G. Hinks and J. D. Jorgensen},
journal= {arXiv preprint arXiv:cond-mat/0103538},
year = {2009}
}
Comments
revised version of paper submitted for publication on March 26, 2001