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arXiv · 2407.00376

Magnetic structure and electronic properties of mixed-metal Ruddlesden-Popper oxide LaSrCo$_{1/2}$Fe$_{1/2}$O$_4$

Dina I. Fazlizhanova·Ruslan G. Batulin·Tatiana I. Chupakhina·Yulia. A. Deeva·Sergey V. Levchenko
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Abstract

Atomic, electronic, and magnetic structure of LaSrCo$_{1/2}$Fe$_{1/2}$O$_4$ mixed-metal Ruddlesden-Popper oxide is investigated theoretically using self-consistent ACBN0 DFT + $U$ approach. We show that the electronic and magnetic properties strongly depend on the distribution of transition-metal and La/Sr ions in the lattice. Fe-Fe exchange is found to be antiferromagnetic, whereas Co-Co and Fe-Co exchange is ferromagnetic. We find that Co spin states depend on the distribution in both La/Sr and transition-metal ions. The most energetically favorable configuration is ferromagnetic, whereas the majority of metastable configurations are antiferromagnetic. LaSrCo$_{1/2}$Fe$_{1/2}$O$_4$ was synthesized using spray-pyrolysis method. Magnetization measurements revealed antiferromgnetic behavior, thus indicating presence of metastable configurations in the synthesized material. In addition, we show that in complex systems, such as mixed-metal Ruddlesden-Popper phases, Hubbard $U$ values have to be determined for each crystallographically non-equivalent site.

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Dina I. Fazlizhanova, Ruslan G. Batulin, Tatiana I. Chupakhina, Yulia. A. Deeva, Sergey V. Levchenko. 2024-06-29. Magnetic structure and electronic properties of mixed-metal Ruddlesden-Popper oxide LaSrCo$_{1/2}$Fe$_{1/2}$O$_4$. https://arxiv.org/abs/2407.00376

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