Comparative study of FeCr2S4 and FeSc2S4: Spinels with orbitally active A site

ion, their properties are rather dissimilar. Our study unravels the microscopicorigin of their behavior driven by the differences in hybridization of Fe d states with Cr/Sc d statesand S p states in the two cases. This leads to important differences in the nature of the magneticexchanges as well as the nearest versus next nearest neighbor exchange parameter ratios, resultinginto significant frustration effects in FeSc