Thermoelectric and electrical characteristics of SmS ceramic samples after exposure to a pulsed magnetic field

Samarium monosulfide(SmS)is a promising material for creating thermoelectric generators(TEG),gas sensors and strain gauges.Despite the high values of the generated thermo electromotive force(TEMF)(α≈170-350μV/K),methods for increasing the efficiency of TEGs based on SmS are of considerable interest.One of these methods can be short-term effects of magnetic fields,including pulsed ones,on these materials.The action of a pulsed magnetic field(PMF)leading to an increase in TEMF(U)of SmS ceramic samples is found.Samples that are not subjected to high frequency currents(HFC)annealing show an increase in UT of 44.54%-62.18%(from 11.9 to 17.2-19.3 mV).The conductivity(σ)of the samples is~22 Q/cm and is insensitive to short-term exposure to a PMF.Samples that undergo HFC annealing show an increase in Uof 23.47%-41.31%(from 21.3 to 26.3-30.1 mV)after exposure to a PMF.The conductivity of the samples is~15Ω^(-1)/cm and after a short exposure to the PMF is changing nonmo notonically,with an increase in the overall instability.The difference in the values of Uand a can be explained by presence of an ordered grain structure and a significant amount of the Sm_(2)O_(2)S phase in the samples subjected to HFC annealing.Possible mechanisms of the observed changes are discussed.