Abstract

GUZMAN, E.J. et al. Increase of Curie temperature with La doping in the double perovskite Sr_2−yLa_yFeMoO₆ within an electronic correlation approach. Rev. mex. fis. [online]. 2018, vol.64, n.2, pp.145-149. ISSN 0035-001X.  https://doi.org/10.31349/revmexfis.64.145.

The double perovskite compound Sr2FeMoO6 has a half-metallic ferromagnetic character and a high Curie temperature (420 K). Fe-Mo usually present some degree of disorder in either Fe or Mo ions, it is therefore fundamental to understand the role of electronic and structural parameters controlling the half-metallic character together with a Curie temperature as high as possible. We replaced divalent Sr2+ by trivalent La3+ ions in Sr2FeMoO6 system to observe the Curie temperature behavior. We present an electronic approach using the Green’s functions and the renormalization perturbation expansion method, with localized Fe-spins and conduction Mo-electrons interacting with the local spins via a double-exchange-type mechanism. We also include the electronic correlations among the conduction electrons within a mean-field approximation. Our results show the density of states and the Curie temperature behavior when La concentration increases for the Sr 2−y La y FeMoO6 system.

Keywords : Double perovskites; Half-metallicity; Curie temperature.

        · text in English     · English ( pdf )