2002/09/11 by Shanti Deemyad, S. Deemyad, T. Tomita +9 · 2 citations
Materials Science · Physics and Astronomy · #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #Thermal Expansion and Ionic Conductivity #cond-mat.supr-con
paper · pdf · doi:10.1016/s0921-4534(02)02300-6
published as Physica C 385, 105 (2003) · Invited paper for a special edition of Physica on MgB2
arxiv created 2002/09/11 · openalex publication_date 2003/01/21 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The dependence of Tc for MgB2 on purely hydrostatic or nearly hydrostatic pressure has been determined to 23 GPa for single-crystalline and to 32 GPa for polycrystalline samples, and found to be in good agreement. Tc decreases from 39 K at ambient pressure to 15 K at 32 GPa with an initial slope dTc/dP = -1.11(2) K/GPa. Evidence is presented that the differing values of dTc/dP reported in the literature result primarily from shear-stress effects in nonhydrostatic pressure media and not differences in the samples. Although comparison of these results with theory supports phonon-mediated superconductivity, a critical test of theory must await volume-dependent calculations based on the solution of the anisotropic Eliashberg equations.