LDA + DMFT and LDA + U study of the electronic and magnetic properties of DyFeSi

Abstract

Considering the strong correlation between 4f electrons in the rare earths has major effect on the calculated electronic and magnetic properties of compounds including rare earths, as neglecting this strong correlation in density functional theory (DFT) leads to the failing DFT for a proper description of mentioned properties. In this study, to consider the strong correlation between 4f electrons in Dy atom of DyFeSi compound, local Coulomb repulsion between 4f electrons, U, are treated both statically as in the LDA + U approximation and dynamically as in the dynamical mean-field theory in the Hubbard-I approximation (LDA + DMFT[HI]). In this regards, we apply first principle density functional calculation by using full potential linear muffin-tin orbital (FP-LMTO) method to present a comparative study between the calculated electronic and magnetic properties of DyFeSi within LDA + U and LDA + DMFT[HI] approaches and show that the LDA + DMFT[HI] approach presents so much better results compared to the LDA + U approach. In the magnetic properties we find that the calculation within LDA + DMFT[HI] reproduces the Dy magnetic moments in accordance to the observations and standard model of rare earth with the best accuracy. In the electronic properties we show that LDA + U just produces narrow energy bands of 4f-electrons and it is not able to produce atomic multiples features of 4f valance bands, while LDA + DMFT[HI] approach shows peaks caused by the formation of atomic multiples of the Dy atoms in DyFeSi compound.