Abstract
The Verwey transition in Eu3S4 at TV = 186 K is explained on the basis of a model which takes into account the Coulomb interaction of the extra 4f electrons at the Eu2+ ions and the formation of small polarons due to the interaction with phonons. This model is treated in the Hartree and cluster variation approximations. At TV a first‐order Verwey transition is obtained. The magnitude of the observed entropy change at TV is explained. Above TV the polarons are found to be considerably short‐range ordered.