Theory of Thermoelectric Power of Ionic Crystals (I)

Abstract

A theory of the thermoelectric power in AgBr is developed, in which the experimental conditions are properly considered. The gradient of the electrochemical potential of silver ions is calculated, since it is related to the quantity measured by the potentiometer, that is, the difference between the Fermi levels at two free ends of lead wires. An expression for the thermoelectric power is derived, which is applicable to AgBr mixed with CdBr ₂ at arbitrary temperatures. The Peltier and Thomson coefficients in the steady state are independently calculated for this special case, and the result shows that the Kelvin relations are really statisfied in the steady state. Finally, the theory is compared with the experiments of Patrick and Lawson.