Magnetic properties of Pd, Pd-H and Pd-D from 300 degrees K to 4.2 degrees K

The magnetic properties of many substances first studied seriously by Faraday have played an important role in our modern technology. In particular, the magnetic properties of the transition elements are of great importance in the understanding of the electronic band form of these elements. Once the electronic band form is known, many of the physical properties may be predicted. Although many investigations have been made of the magnetic properties of palladium, no recent measurements have been reported at temperatures lower than 20° K.

There is some discrepancy between the earlier work of Onnes and Oosterhuis (1913, 1914) and the later work of Hoare and Matthews (1952). There is reason to believe that the later work is correct because of the purity of the samples, but the data indicate a necessity for measurements at temperatures below 20° K.

Palladium adsorbs enormous amounts of hydrogen and a study of this effect could lead to information which would be valuable in the interpretation of the magnetic properties of palladium. The magnetic susceptibility of hydrogenized palladium was studied first by Graham (1869). Since that time it has been shown by Svensson (1953) that the susceptibility of palladium diminishes linearly with increasing hydrogen content and finally reaches a value just below zero for a H/pd volume ratio of 800/1. This same effect was shown to occur by Sieverts and Danz (1937) when deuterium is substituted for hydrogen. Recently, Wucher (1952) has made a study of the variation of the susceptibility of hydrogenized palladium with temperature from -98.6° C to 16.3° C. However, later measurements of the resistivity and thermoelectric power of hydrogenized palladium by Schindler and Smith (1979) indicate that there might be a magnetic anomaly in hydrogenized palladium at 40° K.

The purpose of this work is to extend the previous measurements down to 4.2° K, but measurements will be made on desorbed as well as adsorbed samples of hydrogenized and deuterized palladium. The results on the desorbed samples turned out to be quite interesting and suggest further experiments.