The Seebeck Effect is the conversion of temperature differences directly into electricity. In other words, it is the generation of electricity in a circuit containing two different metals, or semiconductors, by keeping the junctions between them at different temperatures. This effect is due to two effects - Charge Carrier Diffusion and Phonon Drag. This principle is used in thermal diodes and thermoelectric generators.
The Seebeck Voltage is the voltage produced between the two junctions of a ferrite material, when they are maintained at two different temperatures. This voltage is produced due to the fact that when two junctions are two different temperatures, the majority charge carriers (holes/electrons) are diffused from the surface having high temperature to a surface having relatively low temperature.
This voltage can be mathematically expressed as V = (integral)(T1 to T2) [SB(T) - SA(T)]dT where SA and SB are Seebeck coefficients of two different metals A and B, T1 and T2 are temperatures of hot and cold junctions. Generally, V = (SB - SA)(T2 - T1).