Solubility of hydrogen in amorphous Pd1-xSix alloys as hydrogen permeable membranes

Hydrogen solubility of amorphous Pd1-xSix (x = 0.15, 0.175, 0.2) alloys in the form of ribbon, which were prepared with a single-roller melt spinning technique, was measured by a pressure-variable method at elevated temperatures up to 200 degrees C. It was found that the hydrogen solubility in the amorphous alloys, strongly depending on the Si content, decreased with an increase in the Si content, and never obeyed the Sieverts law. The amorphous alloys showed 3-4 times higher hydrogen solubility than the corresponding crystallized ones. Based on the theory proposed by Kirchheim et al., an attempt was made to postulate a simplified equation to describe the relation between the pressure and composition of hydrogen in the amorphous alloys. As a result, similar to the half power law for the crystalline metal, the so-called nth power law with respect to pressure was found to be applicable for the amorphous Pd1-xSix alloys.