Upper critical field and resistivity of single-crystal ${\mathrm{EuBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{\mathrm{y}}$: Direct measurements under high field up to 50 T

A wide-temperature-range profile of the $H_{c2}$-T curve for the superconducting 1:2:3 compound is presented. The data were obtained from a ${\mathrm{EuBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{\mathrm{y}}$ single crystal under a pulsed magnetic field up to 50 T along the c axis. $H_{c2}$ at 4.2 K is 27.5±2.5 T for the onset of the resistivity. The residual resistivity is roughly estimated to be about 50 μΩ cm. The magnetoresistance is positive and the general features of the superconducting properties except $T_c$ are well sketched by the Bardeen-Cooper-Schrieffer dirty-limit model. The anisotropies in $H_{c2}$ and the resistivity are also discussed.