AC electrical resistance measurements of PdHx samples versus composition x

A brief introduction on the transport properties of PdHx system will be presented. The resistance ratio method is the most frequent technique used to measure the interstitial loading of hydrogen atoms into palladium. Using this technique a series of AC electrical resistance measurements of PdHx, demonstrating a stoichiometric values x > 1 obtained by electrochemical method at room temperature and pressure is presented.A full description of the used electrochemical method for preparing the samples PdHx with composition x > 1 and the analysis to determine the achieved composition will be presented.Conclusions on the electrical resistance of PdHx versus composition x and correlated physical phenomena have been done.In particular, these studies show the importance of the electrochemical processes efficiency. In order to have an accurate calculation of x value, precise efficiency amplitude estimation is needed. Our analysis underline the systematic underestimation of the x value in the well known PdHx relative electrical resistance versus x at room temperature as reported in literature.