Comparative description of magnetic interactions in Sr₂CuTeO₆ and Sr₂CuWO₆

In this work, we comparatively explored the electronic structure and the low-dimensional magnetic interactions of double-perovskite compounds Sr₂CuTeO₆ and Sr₂CuWO₆ through first-principles calculations. The electronic structure calculations indicate that the Cu²⁺ (3d ⁹) site is the only magnetic active one, whereas Te⁶⁺ and W⁶⁺ remain in nonmagnetic states with d ¹⁰ and d ⁰ electronic configurations, respectively. The magnetic exchange interactions have been evaluated on the basis of the classical Heisenberg model. Both Sr₂CuTeO₆ and Sr₂CuWO₆ should be strong frustrated 2D magnetism, in excellent agreement with the experimental observations. Nevertheless, the nearest-neighbor antiferromagnetic interaction J ₁ plays a determined role in constructing the Néel antiferromagnetic ordering within the square Cu²⁺ framework of Sr₂CuTeO₆. While, the next-nearest-neighbor antiferromagnetic interaction J ₂ transcends the nearest-neighbor interaction J ₁, establishes the collinear antiferromagnetic ordering in Sr₂CuWO₆. The discrimination has been explored and analyzed in detail using density of states, charge density as well as spin density analysis.