Anisotropy of the Upper Critical Field and Critical Current in Single Crystal MgB$_2$

L. Lyard; P. Samuely; P. Szabo; T. Klein; C. Marcenat; L. Paulius; K. H. P. Kim; C. U. Jung; H. -S. Lee; B. Kang; S. Choi; S. -I. Lee; J. Marcus; S. Blanchard; A. G. M. Jansen; U. Welp; G. Karapetrov; W. K. Kwok

doi:10.1103/PhysRevB.66.180502

paper

Anisotropy of the Upper Critical Field and Critical Current in Single Crystal MgB $_{2}$

arXiv:cond-mat/0206231 · doi:10.1103/PhysRevB.66.180502

Abstract

We report on specific heat, high magnetic field transport and $a c -$ susceptibility measurements on magnesium diboride single crystals. The upper critical field $H_{c 2}$ for magnetic fields perpendicular and parallel to the Mg and B planes is presented for the first time in the entire temperature range. A very different temperature dependence has been observed in the two directions which yields to a temperature dependent anisotropy with $I^ \sim$ 5 at low temperatures and about 2 near $T_{c}$ . A peak effect is observed in susceptibility measurements for $H \sim$ 2 T parallel to the $c -$ axis and the critical current density presnts a sharp maximum for $H$ parallel to the ab-plane.

6 pages, 5 figures

Anisotropy of the Upper Critical Field and Critical Current in Single Crystal MgB2​

Abstract

Anisotropy of the Upper Critical Field and Critical Current in Single Crystal MgB $_{2}$