Paramagnetic Effect in Superconductors. V. Resistance Transition of Tin Wires

The resistance of tin wires between 0.15 and 3 mm in diameter has been measured as a function of the current in the transition region to superconductivity. The samples used were, with one exception, single crystals and had residual-resistance ratios $r_0=\frac{R_{0°\mathrm{K}}}{R_{273°\mathrm{K}}}$ of a few times ${10}^{-5\mathrm{}}$. Most of the transition curves showed a steep rise and a break at the critical current. The critical resistance, defined as the resistance at the break of the curves, is for single crystals independent of the temperature between 1.9°K and the critical temperature, if proper corrections for the temperature dependence and the field dependence of the resistivity are made. Extensive measurements of these dependences have been made for this purpose.