Effect of nonstoichiometry on the Hall effect, Nernst‒Ettingshausen effect, and electrosound in (MnSe)1‒х(Tm0.76Se)х manganese selenides
https://doi.org/10.1016/j.jssc.2025.125284
In nonstoichiometric (MnSe)1‒х(Tm0.76Se)х manganese selenide, the temperature and concentration regions with the same sign of carriers determined from the Hall constant and thermoelectric power have been found. The correlation of the temperature dependences of the thermopower and electrosound has been explained within the polaron model. A change in the sign of the longitudinal and transverse Nernst‒Ettingshausen coefficients upon variation in temperature and concentration has been detected. The agree of the temperature dependences of the Nernst‒Ettingshausen coefficients with a change in the electrosound in a magnetic field has been established. The maxima of the thermopower and Nernst‒Ettingshausen coefficients versus temperature have been explained within the model of coupled electron‒hole pairs with dissociation of the pairs and pinning of coupled polarons.