Transport properties of some hydrogenated nickel-based alloys

Nickel-based alloys - Ni0.98Ti0.02, Ni0.4Cu0.6 (constantan) and Ni0.9Cr0.1 (chromel) have been saturated with hydrogen at ca. 1 GPa at room temperature. The electrical resistance and thermoelectric power of the hydrogenated samples have been simultaneously measured in the temperature range between 80 and 300 K. The electrical resistance of Ni-Ti/H and Ni-Cu/H alloys exhibits an anomalous behavior. The temperature dependent component of the resistance of the Ni0.98Ti0.02 alloy increases upon hydrogenation and continues its increase when hydrogen is desorbed in a stepwise manner. The hydrogenation of Ni0.4Cu0.6 results in a decrease of electrical resistance while the opposite effect is usually observed in other hydrogenated Pd- and Ni-based alloys.