Resumen de Increase of Curie temperature with La doping in the double perovskite Sr_(2−y)La_(y)FeMoO_(6) within an electronic correlation approach
E.J. Guzmán, F. Estrada, B. Aguilar, O. Navarro, M. Avignon
The double perovskite compound Sr_(2)FeMoO_(6) 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 Sr^(2+) by trivalent La^(3+) ions in Sr_(2)FeMoO_(6) 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)FeMoO_(6) system.
