THERMOELECTRIC-POWER OF (NIMN)-H AND (NICO)-H SYSTEMS

Thermoelectric power of Ni95Co5, Ni90Co10 and Ni90.7Mn9.3, Ni82.5Mn17. 5 alloys was measured as a function of hydrogen pressure up to 1.7 GPa for nickel-cobalt and up to 1.0 GPa for nickel-manganese alloys. For the last alloys the change of thermopower during the hydride formation is positive and approaches the value characteristic for pure copper. The behavior of nickel-cobalt alloys was, unexpectedly, different from that of all other nickel alloys investigated so far. When 5 at.% of c obalt is dissolved. in nickel the hydride forms at 25 degrees C almost without change of thermopower. When the concentration of cobalt incre ases to 10 at.% the hydride formation is accompanied by a large negati ve change of thermopower. A qualitative interpretation is proposed.