Gigantic diffusion EMF in zirconium hydride

Electromotive force (EMF) arising in isothermal conditions between two disconnected ends of a zirconium hydride current conductor having a gradient of hydrogen concentration has been investigated at temperatures ranging from 20 to 100 degrees centigrade in water bath. The values of the diffusion EMF, measured in isothermal conditions, fall in the range of 0 to 20 μV depending on the hydrogen concentration difference. The activation energy calculated for experimental data on EMF is equal to 23 kJ/mole at temperatures below 70o C and to 52 kJ/mole at temperatures above 70 degrees centigrade. The activation energy value at high temperatures is close to the activation energy of hydrogen diffusion in zirconium hydrides. It was concluded, that the proposed mechanism of the diffusion EMF origin does not allow to reach an agreement between calculated and measured value of the EMF