Triple A-Site Columnar Ordered Y2CuGaTM4O12 (TM = Mn and Fe) Quadruple Perovskites for Spintronic Applications.

Generalized gradient approximation with Hubbard potential (GGA + U) within the framework of density functional theory (DFT), the structural and electronic properties, as well as the magnetic ordering of the quadruple perovskites Y2CuGaTM4O12 (TM = Mn and Fe), are studied. Formation energy indicates that Y2CuGaMn4O12 is more stable than the Y2CuGaFe4O12 and the estimated structural parameters are in good accordance with the experiment. The optimized magnetic energy curves show that these compounds have a type I ferrimagnetic order. According to the Heisenberg model, strong long-range Mn+3–O2−–Cu2+–O2−–Mn+3 interactions are mediated by a super exchange mechanism. The susceptibility data shows that these compounds undergo multiple magnetic transitions due to different magnetic interactions (J1 (Cu+2–Cu+2), J2 (Cu+2–Mn+3), and J3 (Mn+3–Mn+3)). The electronic band profiles and density of states shows the half-metallic character of these compounds and Mn d electrons are responsible for their half-metallic nature. Beside this Mn d state electrons are also responsible for magnetism with addition of Cu atoms instead of Ga. DFT and the Heisenberg model's estimated results are confirmed by magnetic susceptibility. These compounds are anticipated to be appropriate for spintronic applications due to their ferrimagnetic nature and high spin polarization near the Fermi level. [ABSTRACT FROM AUTHOR]