Investigation of the behavior of electrical resistance and thermal EMF of polycrystals of ytterbium monosulfide during temperature cycling in the range of 320–790 K

The temperature dependences of the electrical resistance $R$ and thermal EMF $S$ of polycrystals of ytterbium monosulfide (YbS) in the range 320–790K have been studied. It was found that cyclic temperature exposure to YbS samples leads to the appearance of hysteresis on the dependences $\ln[R(10^3/T)]$ and $S(T)$. The analysis of the discovered patterns in the behavior of $R$ and $S$ allowed us to suggest a significant influence of the processes of occurrence and destruction of the exciton spectrum during temperature changes on the transport properties of charge carriers in YbS.