Superconductivity in the palladium‐hydrogen system

Superconductivity has been investigated in palladium hydride samples prepared electrolytically. At H/Pd ratios higher than 0.77 a strong dependence of the superconducting critical temperature on H/Pd ratio has been observed. The critical temperature of 6.6 K was found at H/Pd = 0.94. Extrapolation of the experimental data up to H/Pd = 1 gave the critical temperature of stoichiometric PdH about 11 K. It is shown that the normal residual resistivity of a sample can be used for an estimation of the hydrogen content. The measurements of the electrical resistance in the magnetic field revealed a linear dependence of the critical magnetic field on temperature. Extrapolation of H c down to T = 0 gave an H c (0) value equal to 1800 Oe independent of H/Pd.